阅读说明：本技术 用于旋转爆震燃烧的系统 (System for rotary detonation combustion ) 是由 K·K·辛赫 T·M·拉弗图 T·E·戴森 S·M·莫纳罕 V·E·坦吉拉拉 J·M·海恩 于 2020-10-14 设计创作，主要内容包括：本发明涉及用于旋转爆震燃烧的系统。本文中提供了用于旋转爆震燃烧的系统。该系统包括：内壁和外壁,其各自围绕中心线轴线延伸,其中爆震室限定在内壁和外壁之间；以及迭代结构,其定位在内壁或外壁中的一者或两者处。迭代结构包括对应于第一压力波衰减的第一阈结构和对应于第二压力波衰减的第二阈结构。迭代结构提供在爆震室中沿着第一周向方向的压力波加强,或者提供沿着与第一周向方向相反的第二周向方向的压力波减弱。第一周向方向对应于爆震室中的压力波传播的期望方向。(The invention relates to a system for rotary detonation combustion. Systems for rotary detonation combustion are provided herein. The system comprises: an inner wall and an outer wall each extending about a centerline axis, wherein a detonation chamber is defined between the inner wall and the outer wall; and an iterative structure positioned at one or both of the inner wall or the outer wall. The iterative structure includes a first threshold structure corresponding to the first pressure wave attenuation and a second threshold structure corresponding to the second pressure wave attenuation. The iterative structure provides pressure wave intensification in a first circumferential direction in the detonation chamber, or provides pressure wave attenuation in a second circumferential direction opposite the first circumferential direction. The first circumferential direction corresponds to a desired direction of propagation of pressure waves in the detonation chamber.)

1. A system for rotary detonation combustion, the system comprising:

an inner wall and an outer wall each extending about a centerline axis, wherein a detonation chamber is defined between the inner wall and the outer wall;

an iterative structure positioned at one or both of the inner wall or the outer wall, wherein the iterative structure includes a first threshold structure corresponding to a first pressure wave attenuation and a second threshold structure corresponding to a second pressure wave attenuation, wherein the iterative structure provides pressure wave intensification in a first circumferential direction in the detonation chamber or provides pressure wave attenuation in a second circumferential direction opposite the first circumferential direction, and wherein the first circumferential direction corresponds to a desired direction of pressure wave propagation in the detonation chamber.

2. The system of claim 1, wherein the iterative structure comprises an arcuate portion, wherein the arcuate portion comprises the first threshold structure and the second threshold structure.

3. The system of claim 1, wherein the iterative structure comprises a waveform extending in a radial direction from one or more of the inner wall or the outer wall.

4. The system of claim 3, wherein the iterative structure comprising a waveform further comprises a first wall and a second wall that together define a ramp structure extending circumferentially in the detonation chamber, the ramp structure extending radially from one or more of the inner wall or the outer wall.

5. The system of claim 3, wherein the waveform comprises one or more of a triangular wave, a square wave, a sawtooth wave, a sine wave, or a combination thereof.

6. The system of claim 3, wherein the second wall extends substantially tangentially from the first wall to the inner or outer wall to which the first wall is connected.

7. The system of claim 3, wherein the second wall extends from the first wall at a first radial height in a concave, convex, or sinusoidal fashion to the inner or outer wall to which the first wall is connected.

8. The system of claim 1, wherein the iterative structure comprises two or more arcuate portions at the detonation chamber, wherein each arcuate portion of the iterative structure comprises: a radial wall extending from one or more of the inner wall or the outer wall to a first radial height; and a second wall extending from the first radial height at the radial wall to the inner wall or the outer wall to which the radial wall is connected.

9. The system of claim 8, wherein the second wall extends from the radial wall along the desired direction of propagation of pressure waves in the detonation chamber.

10. The system of claim 8, wherein the first radial height is between 3% and 50% of a flow path height, wherein the flow path height extends from the inner wall to the outer wall.

Technical Field

The present subject matter generally relates to a system for continuous detonation in a heat engine, such as a propulsion system.

Background

Many propulsion systems, such as gas turbine engines, are based on the brayton cycle, in which air is compressed adiabatically, heat is increased at a constant pressure, the resulting hot gases are expanded in a turbine, and heat is rejected at a constant pressure. Energy in excess of that required to drive the compression system may then be used for propulsion or other work. Such propulsion systems typically rely on deflagration combustion to incinerate the fuel/air mixture and produce combustion gas products that travel at a relatively slow rate and constant pressure within the combustion chamber. While Brayton cycle based engines have achieved high levels of thermodynamic efficiency through steady improvements in component efficiency and increases in pressure ratio and peak temperature, further improvements remain welcome.

Accordingly, improvements in engine efficiency have been sought by modifying the engine architecture so that combustion occurs as knock in a continuous mode. The high energy ignition causes the fuel/air mixture to knock, which is converted to a detonation wave (i.e., a rapidly moving shock wave closely coupled to the reaction zone). The detonation wave travels within a mach number range greater than the speed of sound of the reactants relative to the speed of sound of the reactants. The combustion products follow the detonation wave at sonic velocity and at significantly elevated pressure relative to the detonation wave. Such combustion products may then exit through the nozzle to generate thrust or rotate the turbine.

However, continuous detonation systems face the challenge of generally maintaining detonation or maintaining detonation across a variety of operating conditions. Without sustaining detonation of the fuel/air mixture, the detonation combustion system may not be able to operate adequately for use in a heat engine. As such, there is a need for methods and systems for maintaining knock of a fuel/air mixture at a knocking combustion system.

Disclosure of Invention

Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

Systems for rotary detonation combustion are provided herein. The system comprises: an inner wall and an outer wall each extending about a centerline axis, wherein a detonation chamber is defined between the inner wall and the outer wall; and an iterative structure positioned at one or both of the inner wall or the outer wall. The iterative structure includes a first threshold structure corresponding to the first pressure wave attenuation and a second threshold structure corresponding to the second pressure wave attenuation. The iterative structure provides pressure wave intensification in a first circumferential direction in the detonation chamber, or provides pressure wave attenuation in a second circumferential direction opposite the first circumferential direction. The first circumferential direction corresponds to a desired direction of propagation of pressure waves in the detonation chamber.

Technical solution 1. a system for rotary detonation combustion, the system comprising:

an inner wall and an outer wall each extending about a centerline axis, wherein a detonation chamber is defined between the inner wall and the outer wall;

an iterative structure positioned at one or both of the inner wall or the outer wall, wherein the iterative structure includes a first threshold structure corresponding to a first pressure wave attenuation and a second threshold structure corresponding to a second pressure wave attenuation, wherein the iterative structure provides pressure wave intensification in a first circumferential direction in the detonation chamber or provides pressure wave attenuation in a second circumferential direction opposite the first circumferential direction, and wherein the first circumferential direction corresponds to a desired direction of pressure wave propagation in the detonation chamber.

Solution 2. the system of any preceding solution, wherein the iterative structure comprises an arcuate portion, wherein the arcuate portion comprises the first threshold structure and the second threshold structure.

Solution 3. the system of any preceding solution, wherein the iterative structure comprises a waveform extending in a radial direction from one or more of the inner wall or the outer wall.

Solution 4. a system according to any preceding solution, wherein the iterative structure comprising a waveform further comprises a first wall and a second wall that together define a ramp structure extending circumferentially in the detonation chamber, the ramp structure extending radially from one or more of the inner wall or the outer wall.

Solution 5. the system according to any preceding solution, wherein the waveform comprises one or more of a triangle wave, a square wave, a sawtooth wave, a sine wave, or a combination thereof.

Solution 6. the system of any preceding solution, wherein the second wall extends substantially tangentially from the first wall to the inner or outer wall to which the first wall is connected.

Solution 7. the system according to any preceding solution, wherein the second wall extends from the first wall at a first radial height in a concave, convex or sinusoidal fashion to the inner or outer wall to which the first wall is connected.

The system of any preceding claim, wherein the iterative structure comprises two or more arcuate portions at the detonation chamber, wherein each arcuate portion of the iterative structure comprises: a radial wall extending from one or more of the inner wall or the outer wall to a first radial height; and a second wall extending from the first radial height at the radial wall to the inner wall or the outer wall to which the radial wall is connected.

Solution 9. the system of any preceding solution, wherein the second wall extends from the radial wall along the desired direction of propagation of pressure waves in the detonation chamber.

The system of any preceding claim, wherein the first radial height is between 3% and 50% of a flow path height, wherein the flow path height extends from the inner wall to the outer wall.

Solution 11. the system of any of the preceding claims, wherein the first radial height is between 3% and 25% of a flow path height, wherein the flow path height extends from the inner wall to the outer wall.

Solution 12. the system according to any preceding solution, wherein the second wall extends at least partially tangentially from the first wall to the inner or outer wall to which the first wall is connected.

Solution 13. the system of any preceding solution, wherein the system iteration structure comprises two or more arcuate portions arranged circumferentially in the detonation chamber.

Solution 14. a system according to any preceding solution, characterized in that it comprises between two and two hundred arcuate sections of said iterative structure arranged circumferentially in said detonation chamber.

The system of any preceding claim, wherein the iterative structure comprises:

a first radial wall extending from one or more of the inner wall or the outer wall to a first radial height;

a second radial wall extending from one or more of the inner wall or the outer wall to a second radial height less than the first radial height;

a first sloped wall extending from the first radial height at the first radial wall to the inner wall or the outer wall from which the first radial wall extends; and

a second sloped wall extending from the second radial height at the second radial wall to the inner wall or the outer wall from which the second radial wall extends.

The system of any preceding claim, wherein the first sloped wall and the second sloped wall each extend to the inner wall or the outer wall along the desired direction of propagation of pressure waves.

The system according to any of the preceding claims, further comprising:

a fuel injector extending in a longitudinal direction, wherein a fuel injector outlet is positioned in a region between the second wall and the first wall.

The system of any preceding claim, wherein the fuel injector outlet is positioned between the inner or outer wall from which the first wall extends and the first radial height of the first wall.

The system of any preceding claim, wherein the fuel injector outlet is positioned upstream of the ramp structure.

Solution 20. a system according to any preceding solution, wherein the fuel injector is positioned at a substantially tangential angle relative to a detonation path in the detonation chamber towards the desired direction of propagation of the pressure wave.

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Drawings

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:

FIG. 1 is a schematic illustration of a heat engine including a rotary detonation combustion system, according to an exemplary embodiment of the present disclosure;

FIG. 2 is a schematic illustration of an exemplary embodiment of a rotary detonation combustion system, in accordance with aspects of the present disclosure;

FIG. 3 is a perspective view of a detonation chamber of the exemplary rotary detonation combustion system of FIG. 2;

FIG. 4 is a downstream-looking upstream view of an exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 5 is a downstream-upstream view of another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 6 is a downstream-upstream view of yet another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 7 is a downstream-upstream view of yet another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 8 is a downstream-looking upstream view of an exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 9 is a side view of a portion of an exemplary embodiment of the rotary detonation combustion assembly of FIG. 8;

FIG. 10 is a flow path view of an exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 11 is a side view of a portion of the exemplary embodiment of the rotary detonation combustion assembly of FIG. 10;

FIG. 12 is a flow path view of another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 13 is a side view of a portion of the exemplary embodiment of the rotary detonation combustion assembly of FIG. 12;

FIG. 14 is a flow path view of an exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 15 is a side view of a portion of the exemplary embodiment of the rotary detonation combustion assembly of FIG. 14;

FIG. 16 is a graph depicting an emission coefficient versus fuel injector position for an exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 17 is a flow path view of an exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 18 is a flow path view of another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 19 is a flow path view of yet another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 20 is a flow path view of yet another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 21 is a flow path view of yet another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 22 is a flow path view of yet another exemplary embodiment of a rotary detonation combustion assembly, in accordance with aspects of the present disclosure;

FIG. 23 is an exemplary embodiment of a vehicle including a rotary detonation combustion system, in accordance with aspects of the present disclosure; and

FIG. 24 is an exemplary embodiment of a propulsion system including a rotary detonation combustion system, according to aspects of the present disclosure.

Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.

Detailed Description

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. The various examples are provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. It is therefore intended that the present invention cover such modifications and variations as come within the scope of the appended claims and their equivalents.

As used herein, the terms "first," "second," and "third" may be used interchangeably to distinguish one component from another component and are not intended to denote the position or importance of the individual components.

The terms "forward" and "aft" refer to relative positions within the propulsion system or vehicle, and to normal operating attitude of the propulsion system or vehicle. For example, with respect to a propulsion system, "forward" refers to a location closer to the propulsion system inlet, and "aft" refers to a location closer to the propulsion system nozzle or exhaust.

The terms "upstream" and "downstream" refer to relative directions with respect to fluid flow in a fluid pathway. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise.

Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about," "approximately," and "substantially," will not be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or of a method or machine for constructing or manufacturing the component and/or system. For example, approximate language may refer to being within a 10 percent margin.

Here and throughout the specification and claims, range limitations are combined and interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

Embodiments of Rotary Detonation Combustion (RDC) systems and methods for operating RDC systems are provided herein. Embodiments of the systems and methods provided herein may maintain substantially unidirectional pressure wave detonation of a fuel/oxidant mixture across a plurality of steady state and transient inlet conditions. Maintaining substantially unidirectional pressure wave detonation of the fuel/oxidant mixture may generally include mitigating or eliminating one or more pressure waves propagating in a direction (e.g., circumferential direction) opposite to the desired unidirectional pressure wave. The counter-rotating pressure waves may generally reduce the sustainability of continuous detonation or reduce the operability of the RDC system across various operating parameters (e.g., idle conditions, maximum power or takeoff conditions, or one or more steady state conditions in between, or transient conditions in between, etc.). Additionally or alternatively, the counter-rotating pressure waves may cause lower quality detonation of the fuel/oxidant mixture and subsequently reduce performance of the RDC system, and the structures and methods provided herein for generating and/or maintaining substantially unidirectional pressure wave detonation may improve performance of the RDC system. Such improved performance may include, but is not limited to, improved steady state and/or transient operability, improved detonation wave maintenance, improved power output, or reduced emissions.

With reference to fig. 1-22, provided herein are embodiments of a rotary detonation combustion system 100 (hereinafter "RDC system 100") and a method 1000 for operation (hereinafter "method 1000") according to exemplary embodiments of the present disclosure. RDC system 100 and method 1000 include structures and methods for operation that may generate one or more substantially unidirectional or co-directional detonation pressure waves along circumferential direction C (fig. 3) at detonation chamber 122. The single/unidirectional or multiple co-directional pressure waves may generally improve the sustainability of the detonation wave, or more particularly, the sustainability of the detonation wave across or between one or more operating parameters. The structures and methods provided herein may further mitigate formation of counter-rotating pressure waves relative to a plurality of substantially co-directional pressure waves, so as to provide a plurality of substantially co-directional pressure waves relative to the circumferential direction C (fig. 3) by the detonation chamber 122.

The RDC system 100 generally includes an outer wall 118 and an inner wall 120 spaced apart from each other along the radial direction R. Together, outer wall 118 and inner wall 120 partially define a detonation chamber 122, a detonation chamber inlet 124, and a detonation chamber outlet 126. The detonation chamber 122 defines a detonation chamber length 123 along the longitudinal centerline axis 116.

Further, the RDC system 100 includes a plurality of fuel injectors 128 located at the detonation chamber inlet 124. The fuel injector 128 provides a flowing mixture of oxidant and fuel to the detonation chamber 122 where such mixture combusts or detonates to produce combustion products therein, and more particularly, a detonation wave 130, as will be explained in greater detail below. The combustion products exit through the detonation chamber outlet 126, such as to the turbine section 106 or an exhaust nozzle, such as described with respect to fig. 1.

In one embodiment, such as depicted in fig. 4, the outer wall 118 and the inner wall 120 are each generally annular and are generally concentric about the longitudinal centerline axis 116. In other embodiments, the outer wall 118 and the inner wall 120 are in a two-dimensional relationship relative to the centerline axis 116 to define a width and a height, or alternatively a variable distance 115 from the centerline axis 116 relative to the angle 114. Together, outer wall 118 and inner wall 120 define a detonation path (e.g., detonation path 410) within detonation chamber 122. The RDC system 100 includes a plurality of fuel injectors 128 arranged adjacent to one another about the centerline axis 116 (such as a circumferential arrangement positioned proximate to one another relative to the centerline axis 116). Although further depicted herein as a circumferential flow path arrangement, it should be appreciated that the various embodiments, features, or elements shown or described with respect to fig. 4-22 may be arranged in a circumferential or two-dimensional relationship.

The fuel injector 128 provides a flowing mixture of oxidant and fuel to the detonation chamber 122 where such mixture combusts/detonates to produce combustion products therein, and more particularly, a detonation wave 130, as will be explained in greater detail below. The combustion products exit through the detonation chamber outlet 126. Although detonation chamber 122 is depicted as a single detonation chamber, in other exemplary embodiments of the present disclosure, RDC system 100 (via outer wall 120 and inner wall 118) may include multiple detonation chambers.

Various embodiments of RDC system 100 include structures that may attenuate or suppress pressure wave formation along a desired direction (i.e., suppress pressure wave formation in a direction opposite to a desired unidirectional or co-directional pressure wave propagation). Embodiments of RDC system 100 provided herein include a plurality of structures that differ from one another along circumferential direction C in order to provide increased pressure wave strength relative to desired circumferential direction C (i.e., first direction 91). The plurality of structures that vary relative to each other along the circumferential direction C may additionally or alternatively mitigate the pressure wave intensification or attenuation relative to a desired circumferential direction opposite the intensification direction (i.e., a second direction 92 opposite the first direction 91).

Since the detonation chamber 122 generally defines an annular space or other flow path extending about the longitudinal axis centerline 116, the plurality of structures provide pressure wave intensification along the first direction 91 and/or pressure wave attenuation along the second direction 92 relative to the initial position. It should be appreciated that in the annular embodiment, the initial position is an initial circumferential position. It should further be appreciated that in a two-dimensional embodiment, the initial position is an initial position relative to the height and width of the detonation chamber 122 and its flow path.

In various embodiments, the initial position is defined at the pre-detonation device 420 extending to the detonation chamber 122. The pre-detonation device 420 is in operative communication with the fuel/oxidant mixture 132 at the detonation chamber 122, such as depicted at fig. 3. In a particular embodiment, the pre-detonation device 420 extends substantially tangentially to a detonation path 410 defined within the detonation chamber 122. Pre-detonation device 420 defines a pre-detonation region 422 tangentially proximate to pre-detonation device 420 at detonation path 410. The pre-detonation device 420 generates a detonation wave 130 of a fuel/oxidant mixture 132 at a detonation chamber 122, such as depicted with respect to FIG. 3. The detonation wave 130 propagates from the pre-detonation zone 422 along the first direction 91.

In some embodiments, a plurality of structures that vary relative to each other along the circumferential direction C provides the iterative structure 150. The iterative structure provides a pressure wave intensification along the first direction 91 and/or a pressure wave attenuation along the second direction 92 from the first threshold to the second threshold. The first threshold corresponds to a first pressure wave attenuation. The second threshold corresponds to a second pressure wave attenuation that is greater than the first pressure wave attenuation. In various embodiments, the iterative structure corresponds to one or more third thresholds defined as being greater than the first threshold and less than the second threshold. The iterative structure may define a waveform, such as a triangular wave. In other embodiments, the iterative structure may define another waveform, such as, but not limited to, a sawtooth waveform, a square wave, a sine wave, and the like. In still other various embodiments, the waveform may define a step wave at which the amplitude of the structure increases before the step decreases to a reduced or initial value, such as further illustrated and described herein. In still other various embodiments, an iterative structure may include between two and forty iterations, or between two and twenty iterations, or between two and ten iterations, of a structure such as that shown and described herein.

In one embodiment, such as further shown and described with respect to fig. 4, the first threshold corresponds to the first height 93 and the minimum structural limit of the detonation path 410. The second threshold corresponds to a second height 94 of knock path 410 that is greater than first height 93 and a maximum structural limit. The iterative structure 150 includes a first wall 151 that extends substantially radially toward the centerline axis 116. The iterative structure 150 further includes a second wall 152 extending substantially tangentially (relative to the detonation chamber 122) from one first wall 151 at the first height 93 to an adjacent or proximate (along the first direction 91) first wall 151 at the second height 94. In one embodiment, the second wall 152 extends substantially linearly between a first height 93 at one first wall 151 (e.g., first wall 151a) and a second height 94 at the other first wall 151 (e.g., first wall 151 b). However, in other embodiments, such as depicted with respect to fig. 5-6, the second wall 152 may be curved, curvilinear, sinusoidal, concave, or convex between the first and second heights 93, 94 of the respective first walls 151a, 151b and from the first height 93 to the second height 94.

It should be appreciated that the second wall 152 extends from a first height 93 at one first wall 151 (e.g., first wall 151a) to a second height 94 of another first wall 151 (e.g., first wall 151 b). Additionally or alternatively, the second wall 152 extends from the first height 93 of the first wall 151 to the respective inner wall 120 or outer wall 118, and the first wall 151 extends from the inner wall 120 or outer wall 118. Furthermore, the sequential arrangement of the iterative structure 150 is positioned such that the second wall 152 extends from the first wall 151 to which the second wall 152 is attached and extends towards the respective inner wall 120 or outer wall 118 to which the respective first wall 151 is attached. The second wall 152 extends further as such and corresponding to a desired circumferential direction C (i.e., the first direction 91) about which the pressure waves 132 are desirably in one or more co-directional orientations. As such, the particular arrangement of the iterative structure 150 including the first wall 151 and the second wall 152 may provide benefits for continuous knock sustainability and operability, such as described herein.

In still other various embodiments, the second walls 152 may differ between respective pairs of the first walls 151. For example, referring to fig. 7, the second wall 152 may define a first profile between the first pair of first walls 151c, 151d, and a second profile between the second pair of first walls 151e, 151f that is different from the first profile. The different profiles may generally correspond to an increased pressure wave intensity along the first direction 91 and/or a desired pressure wave attenuation along the second direction 92.

Referring to fig. 4-7, an iterative structure 150 is defined between each pair of first walls 151 (e.g., first walls 151a, 151 b). In various embodiments, iterative structure 150 is further defined along an arc segment or distance of detonation path 410. Referring to FIG. 7, arcuate portion 155 of detonation chamber 122 includes a second wall 152, second wall 152 defining a first profile corresponding to a first threshold, a second profile corresponding to a second threshold circumferentially spaced along first direction 91, and one or more third profiles between the first and second profiles corresponding to a third threshold. The iterative structure 150 may provide two or more iterations of the arcuate portion 155 along the detonation path 410.

In one embodiment, arcuate portion 155 corresponds to a 180 degree arc (i.e., two arcuate portions) of detonation flow path 410. In another embodiment, arcuate portions 155 correspond to 18 degrees of arc (i.e., 20 arcuate portions) of detonation path 410. In yet another embodiment, arcuate portion 155 corresponds to a 9 degree arc (i.e., 40 arcuate portions) of detonation path 410. In yet another embodiment, arcuate portion 155 corresponds to approximately a 1.8 degree arc (i.e., two hundred arcuate portions) of detonation path 410. In various embodiments, two or more of the arcuate portions 155 can include one or more of a different first height 93, second height 94, profile (i.e., curved or curvilinear, sinusoidal, concave, convex, etc.) of the second wall 152 at one arcuate portion (e.g., arcuate portion 155a) than another arcuate portion 155 (e.g., arcuate portion 155 b).

Referring to fig. 4-7, it should be appreciated that in various embodiments, the first wall 151 extends from the outer wall 118, the inner wall 120, or both. Detonation path 410 defines a flow path height 95 extending between inner wall 120 and outer wall 118. In one embodiment, first height 93 of first wall 151 extends between 3% and 50% of flow path height 95 from either wall 118, 120 into detonation path 410. In another embodiment, first height 93 of first wall 151 extends between 3% and 25% into detonation path 410 from either wall 118, 120.

In a particular embodiment, the detonation path 410 includes at least 1% of the flow path height 95. As such, in particular embodiments where the first walls 151 extend from the inner wall 120 and the outer wall 118, one of the first walls 151 may extend less than the other first wall 151 to provide at least 1% of the flow path height 95 for the fuel/oxidant mixture and the detonation wave propagation. In certain embodiments, the flow path height 95 defines a span from the inner wall 120 to the outer wall 118, such as between 0% and 100%. In various embodiments, first wall 151 extends from inner wall 120 and outer wall 118 into detonation path 410. In one embodiment, first wall 151 extends from inner wall 120 and outer wall 118 to first height 93, wherein a span of 25% or less and a span of 75% or more of detonation path 410 is unobstructed by first wall 151. In another embodiment, first wall 151 extends from inner wall 120 and outer wall 118 to first height 93, wherein a span of 20% or less and a span of 80% or more of detonation path 410 is unobstructed by first wall 151. In yet another embodiment, first wall 151 extends from inner wall 120 and outer wall 118 to first height 93, wherein a span of 10% or less and a span of 90% or more of detonation path 410 is unobstructed by first wall 151. In yet another embodiment, first wall 151 extends from inner wall 120 and outer wall 118 to first height 93, wherein a span of 3% or less and a span of 97% or more of detonation path 410 is unobstructed by first wall 151.

In various further embodiments, the extent to which the first wall 151 extends from the inner wall 120 relative to the first wall 151 extending from the outer wall 118 may be non-uniform or unequal. For example, the first wall 151 may extend from the inner wall 120 into 25% of the span of the flow path height 95, and the first wall 151 may extend from the outer wall 118 into 95% of the span of the flow path height 95.

In certain embodiments, the plurality of first walls 151 and second walls 152 are arranged axisymmetrically about at least a portion of detonation path 410. However, in other embodiments, the plurality of first walls 151 and second walls 152 may be configured in a non-axisymmetrical arrangement.

Still referring to fig. 4-7, it should be appreciated that flow path views of the first wall 151 and the second wall 152 are provided. The first wall 151 extends substantially in the radial direction R relative to the centerline axis 116. The second wall 152 extends at least partially tangentially with respect to the detonation path 410, the inner wall 120 or the outer wall 118, or is substantially tangential with respect to the circumferential direction C.

Referring now to FIG. 8, another flow path view of RDC system 100 is provided. The embodiment provided with respect to fig. 8 is configured substantially similar to that shown and described with respect to fig. 1-7. The RDC system 100 further includes a plurality of fuel injectors 128 configured to provide a flow of liquid and/or gaseous fuel to the detonation chamber 122. Each fuel injector 128 includes a fuel injector outlet 129 through which a flow of fuel and/or fuel/oxidant mixture enters the detonation chamber 122. In one embodiment, such as that depicted in fig. 8, the fuel injector outlet 129 is positioned within a span from the first height 93 to the inner wall 120 or the outer wall 118 such that the fuel injector outlet 129 is positioned within a pocket or region 131 in the detonation path 410 between the first wall 151 and the second wall 152. In various embodiments, the fuel injector outlet 129 is positioned within one or more ranges of the first height (i.e., between the walls 118, 120 and the first height 93 along the radial direction R), such as described above. Positioning the fuel injector outlet 129 within the region 131 may beneficially improve fuel/oxidant mixing and detonation. The fuel injector outlet 129 may further or alternatively improve the formation of substantially unidirectional or co-directional pressure waves in the detonation path 410. However, it should be appreciated that other embodiments may position the fuel injector outlet 129 within the span of the flowpath height 95 radially from the first wall 151 into the detonation path 410 (e.g., within 3% and 97% span, or within 10% and 90% span, or within 20% and 80% span, or within 25% and 75% span, etc., such as described above).

Referring now to fig. 9, a longitudinal side view of the structure 150 is provided. The longitudinal side view of RDC system 100 depicted in fig. 9 may be configured substantially similar to the flow path view of RDC system 100 depicted in fig. 4-8. In fig. 9, the first wall 151 and the second wall 152 each extend along the longitudinal direction L. The first wall 151 and the second wall 152 each define a downstream end 153 proximate the detonation chamber outlet 126. The first and second walls 151 and 152 each further define an upstream end 154 distal from the detonation chamber outlet 126 and the downstream end 153. In various embodiments, the fuel injector outlet 129 is positioned forward or upstream of the downstream end 153 of the walls 151, 152. In one embodiment, the fuel injector outlet 129 may be positioned forward or upstream of the upstream end 154 of the walls 151, 152.

Referring now to fig. 10-11, flow path views of another exemplary embodiment of RDC system 100 are provided. The embodiment shown and described with respect to fig. 10 may include a first wall 151 and a second wall 152, such as shown and described with respect to fig. 4-9. For clarity, fig. 10-11 omit embodiments of the first wall 151 and the second wall 152. In the embodiment depicted with respect to fig. 10-11, the plurality of fuel injectors 128 may be positioned in the RDC system 100 at a substantially tangential angle 127 relative to the annular detonation path 410, such as depicted via reference to the centerline axis 90. In certain embodiments, the fuel injector 128 includes a fuel injector outer wall 125 surrounding a fuel injector centerline axis 225. The fuel injector centerline axis 225 may generally correspond to a direction along which fuel and/or oxidant or fuel/oxidant mixture may be provided to the detonation chamber 122 and extend through the fuel injector 128.

In various embodiments, angle 127 is between approximately 0 degrees and approximately 90 degrees. In a particular embodiment, the angle 127 is between approximately 30 degrees and approximately 60 degrees. In still other various embodiments, the fuel injector outlet 129 of each fuel injector 128, or a plane thereof, is positioned at an angle 127, particularly with respect to the reference centerline axis 90 of the detonation path 410. In certain embodiments, such as described with respect to fig. 4-9, the fuel injector outlets 129 are angled toward a desired unidirectional or co-directional pressure wave propagation, such as along the first direction 91. The angle 127 may provide a desired first direction 91 to the detonation wave 130. The angle 127 of the fuel injector 128 may further mitigate the detonation wave 130 from traveling opposite the angle 127 of the fuel injector 128 and its fuel outlet 129.

Referring now to FIG. 12, a flow path view of another exemplary embodiment of RDC system 100 is provided. Fig. 13 provides a side view of the embodiment depicted in fig. 12. The embodiment provided with respect to fig. 12-13 is configured substantially similar to that shown and described with respect to fig. 4-10. As such, certain features and descriptions that may be applied to the various embodiments of RDC system 100 depicted in fig. 1-11 may be omitted in fig. 12-13 for clarity. The fuel injector 128 may further include a converging-diverging (C/D) nozzle arrangement. The C/D nozzle structure may further define a venturi nozzle. The C/D nozzle or venturi nozzle may provide a coanda effect of the flow of fuel from the fuel injector 128 in the first direction 91.

The coanda effect provided by at least the fuel injector outer wall 125 of the fuel injector 128 may provide a solid surface that at least partially surrounds the jet of fuel and/or oxidant ejected through the nozzle 237 positioned between the converging section 221 and the diverging section 223 of the fuel injector 128. The substantially low pressure region between the fuel injector outer wall 125 and the free jet of fuel and/or oxidant from the nozzle 127 may cause the free jet to adhere to the fuel injector outer wall 125. The fuel injector 128 defining the C/D nozzle may travel opposite the angle 127 of the fuel injector 128 and the fuel outlet 129 generally or further mitigating the detonation wave 130. For example, such as depicted with respect to fig. 12, the fuel/oxidant mixture 132 may exit into the detonation chamber 122 at least partially along the first direction 91. The angle 127 of the fuel injector 128 and/or the C/D nozzle may mitigate the propagation of the detonation wave 130 in the second direction 92 opposite the first direction 91.

Referring now to FIG. 14, a flow path view of another exemplary embodiment of RDC system 100 is provided. Fig. 15 provides a side view of a portion of the embodiment depicted in fig. 14. The embodiments provided with respect to fig. 14-15 are configured substantially similar to that shown and described with respect to fig. 1-13. As such, certain features and descriptions that may be applied to the various embodiments of RDC system 100 depicted in fig. 5-13 may be omitted in fig. 14-15 for clarity. In various embodiments, RDC system 100 provides a first threshold corresponding to a first emission coefficient of a fuel injector 128 and a second threshold corresponding to a second emission coefficient of another fuel injector 128 that is greater than the first emission coefficient, such as described above.

In certain embodiments, such as depicted with respect to fig. 15, the fuel injector outer wall 125 includes a relatively straight or longitudinal portion that defines the fuel passage 323. The fuel injector outer wall 125 further includes a wall 329 that is angled relative to the fuel injector centerline axis 225. An angle 327 of the angled wall 329 relative to the fuel injector centerline axis 225 corresponding to a discharge coefficient of the fuel orifice is defined. In various embodiments, angle 327 corresponding to the discharge coefficient varies between 0 degrees and 90 degrees.

Referring to FIG. 16, a graph depicting variation of emission coefficient with respect to circumferential position of a fuel injector is provided. It should be appreciated that the graph depicted with respect to fig. 16 may generally apply to the iterative structure 150 shown and described herein with respect to fig. 1-15. In various embodiments, the discharge coefficient corresponds to the angled wall 329 and the angle 327 of the fuel injector 128. In one embodiment, the RDC system 100 including the iterative structure includes two or more fuel injectors 128 arranged circumferentially. Each of the plurality of fuel injectors 128 includes a quantity of fuel injectors that define a discharge coefficient (Cd) that increases along a desired direction of propagation of the pressure wave (e.g., the first direction 91). For example, referring to fig. 14-16, the iterative structure includes two or more iterations of the plurality of fuel injectors 128, such as depicted as fuel injectors 228, 328, 428, 528, 628, 728. The fuel injector 228 with the minimum Cd may generally define an iterative minimum emission coefficient (Cd) for the fuel injector. The fuel injector 728 of the maximum Cd may generally define the iterative maximum Cd of the fuel injector. As further depicted in FIG. 16, circumferentially sequential fuel injectors (i.e., sequential with respect to the desired direction of pressure wave propagation) following the largest fuel injector 728 may include the fuel injector 228 with the smallest Cd. In various embodiments, the RDC system 100 may include one or more mid Cd fuel injectors 328, 428, 528, 628 circumferentially positioned between the minimum Cd fuel injector 228 and the maximum Cd fuel injector 728. The fuel injector for mid Cd defines one or more emission coefficients between a minimum Cd and a maximum Cd. In one embodiment, a plurality of fuel injectors (e.g., 328, 428, 528, 628, etc.) with intermediate Cd define equal or increasing Cd in circumferential order between the fuel injector 228 with the smallest Cd and the fuel injector 728 with the largest Cd.

In one embodiment, the change in Cd from the fuel injector 228 with the smallest Cd to the fuel injector 728 with the largest Cd is between 2 and 3 times. In one embodiment, the fuel injector 728 that maximizes Cd defines a discharge coefficient that is three times that of the fuel injector 228 that minimizes Cd. In another embodiment, the fuel injector 728 that maximizes Cd defines an emission coefficient 2.5 times that of the fuel injector 228 that minimizes Cd. In yet another embodiment, the fuel injector 728 that maximizes Cd defines a discharge coefficient twice that of the fuel injector 228 that minimizes Cd.

In still other various embodiments, such as previously stated, RDC system 100 may include between two and forty iteration structures 150. In one embodiment, RDC system 100 includes two iterative structures 150 that repeat in 180 degree line segments or arcs. In yet another embodiment, RDC system 100 includes four iterative structures 150 that repeat in 90 degree line segments or arcs. In another embodiment, RDC system 100 includes eight iterative structures 150 that repeat in 45 degree line segments or arcs. In yet another embodiment, RDC system 100 includes twenty iterative structures 150 that repeat in 18 degree line segments or arcs. In yet another embodiment, RDC system 100 includes forty iterative structures 150 repeated with 9 degree line segments or arcs.

Referring now to fig. 17-22, further flow path views of exemplary embodiments of RDC system 100 are provided. The embodiment provided with respect to fig. 17-22 is configured substantially similar to that shown and described with respect to fig. 1-16. As such, certain features and descriptions that may be applied to the various embodiments of RDC system 100 depicted in fig. 5-16 may be omitted in fig. 17-22 for clarity. In fig. 17-22, various embodiments of RDC system 100 including damper 300 are provided. In certain embodiments, damper 300 defines a Helmholtz resonator defining a fluid reservoir having an opening 305 in fluid communication with detonation chamber 122. The damper 300 defining a helmholtz damper is configured such that the target frequency or range thereof corresponds to a pressure or pressure wave that may be generated in an undesired direction (i.e., opposite the desired direction, such as the second direction 92). Damper 300 may be defined by the following equation:

wherein the content of the first and second substances,fis the frequency of the pressure oscillations to be damped or a range thereof;cis the speed of sound in the fluid (i.e., oxidant or detonation gas);Ais the cross-sectional area of the opening 305 of the damper passage 306 to the air chamber 307;Vis the volume of damper passage 306, air chamber 307, or both; and isL'Is the effective length of the damper passage 306. In various embodiments, the effective length is the length of damper passage 306 plus a correction factor, as is commonly understood in the art, multiplied by the diameter of the area of damper passage 306.

In various embodiments, damper 300 includes a plurality of dampers that define at least a minimum attenuation target (e.g., at damper 301) and a maximum attenuation target (e.g., at damper 303). The plurality of dampers may further include one or more of intermediate attenuation targets (e.g., at damper 302) targeted at one or more frequencies between a minimum attenuation target at damper 301 and a maximum attenuation target at damper 303. The plurality of dampers 301, 302, 303 are configured substantially similar to that shown and described with respect to the graph in fig. 16. As such, the plurality of dampers are arranged in increasing or decreasing order arrangement along the circumferential direction to mitigate pressure wave propagation along an undesired direction (e.g., the second direction 92). In still other various embodiments, RDC system 100 includes two or more dampers 301, 302, 303 arranged such as described above with respect to fig. 1-16.

Referring to fig. 18-20, in certain embodiments, damper 300 defines a fuel cavity 400, and a flow of liquid and/or gaseous fuel is provided from fuel cavity 400 to fuel injector 128. In various embodiments, damper 300 defining fuel cavity 400 provides fuel to one or more fuel injectors 128 in a sequential circumferential arrangement. Damper 300 may provide fuel to a quantity of fuel injectors 128, such as depicted at dampers 301, 302, 303. Damper 300 defining fuel cavity 400 is configured such as shown and described with respect to fig. 1-17.

Still referring to fig. 18-20, various embodiments of multiple dampers 300 are positioned in a circumferential arrangement from either pre-detonation device 420 or pre-detonation zone 422. In certain embodiments, a plurality of dampers 300 are positioned in a circumferential arrangement from either pre-detonation device 420 or pre-detonation zone 422 in an order corresponding to an increase in target frequency in a desired direction of pressure wave propagation (e.g., along first direction 91). Referring to fig. 18-20, plurality of dampers 300 includes a minimum attenuation target damper 301 positioned adjacent or proximate to a pre-detonation device 420 along a desired direction of pressure wave propagation (e.g., first direction 91).

In certain embodiments, such as depicted with respect to fig. 19, a plurality of dampers 300 are arranged in the circumferential direction C in the arcuate portion 155 including the iterative structure 150. The arcuate portion 155 includes a minimum attenuation target damper 301 and a maximum attenuation target damper 303, such as depicted with respect to fig. 19. In some embodiments, the arcuate portion 155 further includes one or more of intermediate attenuation target dampers 302 positioned circumferentially between a minimum attenuation target damper 301 and a maximum attenuation target damper 303, such as depicted with respect to fig. 20. In still other embodiments, the plurality of dampers 300 are positioned in order of increasing target attenuation frequency along the desired direction of pressure wave propagation (e.g., the first direction 91). In the exemplary embodiment depicted in fig. 20, minimum attenuation target damper 301 is positioned proximate or in close proximity to pre-detonation device 420 or pre-detonation zone 422 along the desired direction of pressure wave propagation (e.g., first direction 91). The maximum attenuation target damper 303 may be located next to or in close proximity to the pre-detonation device 420 or pre-detonation zone 422 along the second direction 92 or opposite the desired direction of pressure wave propagation. In certain embodiments, one or more subsequent intermediate attenuation target dampers 302 may be circumferentially placed between the minimum attenuation target damper 301 and the maximum attenuation target damper 303.

Referring to FIG. 21, in various embodiments, the plurality of dampers 300 are configured as fluid diodes having a plurality of fuel nozzles 128. In various embodiments, each damper 300 is fluidly connected to fuel nozzles 128 via fuel circuit 190. The system 100 includes a first fuel circuit 191 configured to provide a flow of fuel in fluid communication to a first fuel nozzle (e.g., fuel nozzle 196). The system 100 further includes a second fuel circuit 192 configured to provide a flow of fuel in fluid communication to a second fuel nozzle (e.g., fuel nozzle 197) circumferentially adjacent the first fuel nozzle 196. Further, the plurality of dampers 300 includes a first damper fluidly coupled to the first fuel nozzle 196 via the second fuel circuit 192 and fluidly coupled to the second fuel nozzle 197 via the first fuel circuit 191. In certain embodiments, the first fuel nozzle 196 is positioned immediately adjacent or proximate to the pre-detonation device 420.

In various embodiments such as shown and described with respect to fig. 17-20 or more generally with respect to fig. 4-20, the plurality of dampers 300 are arranged in a sequence in which the pressure frequency attenuation increases or decreases along the desired direction of pressure wave propagation (e.g., the first direction 91). In the exemplary embodiment, fuel nozzle 128 receives a flow of fuel from first fuel circuit 191 and from a first damper, and further receives fuel from second fuel circuit 192 and from a second damper, where the second damper is positioned circumferentially proximate to the first damper along a desired direction of pressure wave propagation (e.g., first direction 91).

In one embodiment, the plurality of dampers 300 includes a minimum attenuation target damper 301 and a maximum attenuation target damper 303. The plurality of dampers 300 are positioned in order of increasing target frequency of the pressure wave along the desired direction of propagation of the pressure wave (e.g., the first direction 91). In certain embodiments, the plurality of dampers 300 includes a first damper or minimum attenuation target damper 301 positioned proximate the pre-detonation device 420 along the desired direction of pressure wave propagation. A second damper or maximum attenuation target damper 303 is positioned proximate the pre-detonation device 420 in a direction opposite to the desired direction of pressure wave propagation or the desired direction of pressure wave attenuation (e.g., second direction 92). In various embodiments, one or more intermediate attenuation target dampers 302 are positioned circumferentially between dampers 301, 303. In various embodiments, the first damper is configured to have a smaller pressure frequency attenuation than the second damper. For example, the first damper is typically a minimum attenuation target damper 301 or an intermediate attenuation target damper 302, and the second damper is typically an intermediate attenuation target damper 302 (i.e., greater than the minimum attenuation target damper 301 or greater than or equal to another intermediate target damper 302) or a maximum attenuation target damper 303.

In another embodiment, a plurality of dampers 300 are configured such as shown and described with respect to fig. 4-21. In some embodiments, such as depicted in fig. 22, a plurality of dampers 300 are arranged in the arcuate portion 155 along the circumferential direction C. Each arcuate section 155 includes a minimum attenuation target damper 301 and a maximum attenuation target damper 302. In further embodiments, each arcuate portion 155 includes one or more of the intermediate attenuation target dampers 302 circumferentially between dampers 301, 303. It should be appreciated that in the embodiment provided, each damper 300 is configured to be in fluid communication with at least a pair of fuel nozzles 128.

Referring back to fig. 17-22, in various embodiments, the plurality of dampers 300 includes a minimum attenuation target damper 301 and a maximum attenuation target damper 303, wherein the minimum attenuation target damper 301 is positioned circumferentially sequentially (e.g., along the first direction 91) behind the maximum attenuation target damper 303. In certain embodiments, the minimum attenuation target damper 301 is further positioned immediately adjacent or proximate to the pre-detonation device 420 along the circumferential direction C. In still other various embodiments, one or more intermediate attenuation target dampers 302 are positioned circumferentially between dampers 301, 303.

Referring back to FIG. 1, the engine is generally configured as a propulsion system or heat engine 102. More specifically, heat engine 102 generally includes an inlet or compressor section 104 and an outlet or turbine section 106. In various embodiments, RDC system 100 is positioned downstream of compressor section 104. In some embodiments, such as depicted with respect to fig. 1, the RDC system 100 is positioned upstream of the turbine section 106. In other embodiments, such as further illustrated and described with respect to fig. 24, the RDC system 100 is positioned upstream and/or downstream of the turbine section 106. During operation, an airflow may be provided to the inlet 108 of the compressor section 104, where such airflow is compressed by one or more compressors, each of which may include one or more alternating stages of compressor rotor blades and compressor stator vanes. However, in various embodiments, compressor section 104 may define a nozzle through which the air flow is compressed as it flows to RDC system 100.

As will be discussed in more detail below, compressed air from the compressor section 104 may then be provided to the RDC system 100, where the compressed air may be mixed with fuel and detonated to produce combustion products. The combustion products may then flow to the turbine section 106, where one or more turbines may extract kinetic/rotational energy from the combustion products in the turbine section 106. As with the compressor(s) within compressor section 104, each of the turbine(s) within turbine section 106 may include one or more alternating stages of turbine rotor blades and turbine stator vanes. However, in various embodiments, turbine section 106 may define an expansion section through which detonation gases expand and provide propulsive thrust from RDC system 100. In still other various embodiments, the combustion gases or products may then flow from the turbine section 106 through, for example, an exhaust nozzle to generate thrust for the heat engine 102.

As will be appreciated, rotation of the turbine(s) within turbine section 106 produced by the combustion products is transferred through one or more shafts or spools 110 to drive the compressor(s) within compressor section 104. In various embodiments, compressor section 104 may further define a fan section, such as for a turbofan engine configuration, for propelling air across a bypass flow path external to RDC system 100 and turbine section 106.

It will be appreciated that the heat engine 102 schematically depicted in fig. 1 is provided by way of example only. In certain example embodiments, heat engine 102 may include any suitable number of compressors within compressor section 104, any suitable number of turbines within turbine section 106, and may further include any number of shafts or spools 110 suitable for mechanically coupling compressor(s), turbine(s), and/or fans. Similarly, in other exemplary embodiments, heat engine 102 may include any suitable fan section, wherein the fan of the fan section is driven by turbine section 106 in any suitable manner. For example, in certain embodiments, the fan may be directly coupled to the turbine within turbine section 106, or alternatively, may be driven across a reduction gearbox by the turbine within turbine section 106. Further, the fan may be a variable pitch fan, a fixed pitch fan, a ducted fan (i.e., the heat engine 102 may include an outer nacelle surrounding a fan section), an unducted fan, or may have any other suitable configuration.

Moreover, it should also be appreciated that RDC system 100 may further be incorporated into any other suitable aviation propulsion system, such as a supersonic propulsion system, a hypersonic propulsion system, a turbofan engine, a turboshaft engine, a turboprop engine, a turbojet, a ramjet engine, a scramjet engine, or the like, or combinations thereof, such as a combined cycle propulsion system. Further, in certain embodiments, RDC system 100 may be incorporated into a non-airborne propulsion system, such as a land-based power generation propulsion system, an aeroderivative propulsion system, or the like. Further, in certain embodiments, RDC system 100 may be incorporated into any other suitable propulsion system or vehicle, such as manned or unmanned aerial vehicles, rockets, missiles, launch vehicles, and the like. With one or more of the latter embodiments, the propulsion system may not include the compressor section 104 or the turbine section 106, but instead may only include converging and/or diverging flow paths to and from the RDC system 100, respectively. For example, the turbine section 106 may generally define a nozzle 135 through which the combustion products flow to generate thrust.

Referring now to FIG. 2, a side view schematic diagram of an exemplary RDC system 100 as may be incorporated into the exemplary embodiment of FIG. 1 is provided. As shown, the RDC system 100 generally defines a longitudinal centerline axis 116 that may be common with the heat engine 102, a radial direction R relative to the longitudinal centerline axis 116, a circumferential direction C (see, e.g., fig. 3) and a longitudinal direction L (shown in fig. 1) relative to the longitudinal centerline axis 116.

Referring briefly to FIG. 3, a perspective view of the detonation chamber 122 (without the fuel injectors 128) is provided, and it will be appreciated that during operation, the RDC system 100 generates a detonation wave 130. The detonation wave 130 travels in the circumferential direction C of the RDC system 100, thereby consuming the incoming fuel/oxidant mixture 132 and providing a high pressure zone 134 within an expansion zone 136 of combustion. The combusted fuel/oxidizer mixture 138 (i.e., detonation gases) exits the detonation chamber 122 and is exhausted.

More particularly, it will be appreciated that the RDC system 100 is a detonation type combustor that derives energy from the continuous wave 130 of detonation. For a detonation combustor, such as RDC system 100 disclosed herein, combustion of fuel/oxidant mixture 132 is actually detonation as compared to incineration as is typical in conventional deflagration-type combustors. Thus, the main difference between detonation and detonation is related to the mechanism of flame propagation. In deflagration, flame propagation varies with heat transfer from the reaction zone to the fresh mixture, generally by conduction. In contrast, in the case of a detonation combustor, detonation is a shock-induced flame that causes coupling of the reaction zone and the shock. The shock wave compresses and heats the fresh mixture 132, thereby warming such mixture 132 above the auto ignition point. On the other hand, the energy released by the detonation contributes to the propagation of the detonation shock 130. Further, in the case of continuous detonation, the detonation wave 130 propagates around the detonation chamber 122 in a continuous manner, operating at a relatively high frequency. Additionally, the detonation wave 130 may cause the average pressure inside the detonation chamber 122 to be higher than the average pressure within a typical combustion system (i.e., a deflagration combustion system).

Thus, the region 134 behind the detonation wave 130 has a very high pressure. As will be appreciated from the discussion below, the fuel injectors 128 of the RDC system 100 are designed to prevent high pressure within the region 134 behind the detonation wave 130 from flowing in an upstream direction, i.e., into the incoming flow of the fuel/oxidant mixture 132.

Referring back to fig. 1 in conjunction with fig. 2-22, RDC system 100 further includes a controller configured to regulate, modulate, or otherwise desirably provide fuel or a fuel/oxidant mixture through the fuel nozzles, either alone or in combination with two or more fuel nozzles. In general, controller 210 may correspond to any suitable processor-based device, including one or more computing devices. For example, FIG. 1 illustrates one embodiment of suitable components that may be included within controller 210. As shown in fig. 1, the controller 210 may include a processor 212 and associated memory 214 configured to perform a variety of computer-implemented functions (e.g., to perform the methods, steps, calculations, etc., disclosed herein). As used herein, the term "processor" refers not only to integrated circuits referred to in the art as being included in a computer, but also refers to controllers, microcontrollers, microcomputers, Programmable Logic Controllers (PLCs), Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), and other programmable circuits. Additionally, memory 214 may generally include memory element(s) including, but not limited to, a computer-readable medium (e.g., Random Access Memory (RAM)), a computer-readable non-volatile medium (e.g., flash memory), a compact disc-read only memory (CD-ROM), a magneto-optical disc (MOD), a Digital Versatile Disc (DVD), and/or other suitable memory elements or combinations thereof. In various embodiments, the controller 210 may define one or more of a Full Authority Digital Engine Controller (FADEC), a Propeller Control Unit (PCU), an Engine Control Unit (ECU), or an Electronic Engine Control (EEC).

As shown, the controller 210 may include control logic 216 stored in the memory 214. The control logic 216 may include instructions that, when executed by the one or more processors 212, cause the one or more processors 212 to perform operations, such as steps for providing fuel and/or oxidant to operate the substantially unidirectional pressure wave RDC system 100.

In addition, as shown in fig. 1, the controller 210 may further include a communication interface module 230. In several embodiments, the communication interface module 230 may include associated electronic circuitry for transmitting and receiving data. As such, the communication interface module 230 of the controller 210 may be used to send data to the engine 102 and the RDC system 100 and/or receive data from the engine 102 and the RDC system 100. Additionally, the communication interface module 230 may also be used to communicate with any other suitable component of the engine 102, including any number of sensors, valves, flow control devices, orifices, etc., configured to determine, calculate, modify, replace, articulate, adjust, or otherwise provide desired fuel and/or oxidant properties to the detonation chamber 122, including but not limited to fluid flow rates, fluid pressures, fluid temperatures, fluid densities, fluid atomization, etc. It should be appreciated that communication interface module 230 may be any combination of suitable wired and/or wireless communication interfaces, and thus may be communicatively coupled to one or more components of RDC system 100 and engine 102 via wired and/or wireless connections. As such, the controller 210 may obtain, determine, store, generate, transmit, or operate any one or more steps of the method 1000 at the engine 102, a device to which the engine 102 is attached (e.g., an aircraft), or a ground, air, or satellite based device in communication with the engine 102 (e.g., a distributed network).

Referring now to fig. 23, a perspective view of a hypersonic vehicle or hypersonic aircraft 700 is provided, according to an exemplary aspect of the present disclosure. The exemplary hypersonic aerial vehicle 700 of fig. 1 generally defines a vertical direction V, a lateral direction (not labeled), and a longitudinal direction L. Further, the hypersonic aerial vehicle 700 extends generally along the longitudinal direction L between a forward end 702 and an aft end 704. For the illustrated embodiment, hypersonic aerial vehicle 700 includes a fuselage 706, a first wing 708 extending from a port side of fuselage 706, a second wing 710 extending from a starboard side of fuselage 706, and a vertical stabilizer. Hypersonic aircraft 700 includes a propulsion system that, for the illustrated embodiment, includes pairs of hypersonic propulsion engines 102, with a first of such engines 102 mounted below first wing 708 and a second of such engines 102 mounted below second wing 710. As will be appreciated, the propulsion system may be configured for propelling the hypersonic aerial vehicle 700 from takeoff (e.g., 0 miles per hour to about 250 miles per hour) upward to hypersonic flight. It will be appreciated that, as used herein, the term "hypersonic" generally refers to air velocities of about mach 4 up to about mach 10, such as mach 5 and above.

It is noted that the exemplary hypersonic aerial vehicle 700 depicted in FIG. 23 is provided by way of example only, and may have any other suitable configuration in other embodiments. For example, in other embodiments, the fuselage 706 may have any other suitable shape (such as a more pointed aerodynamic shape, a different stabilizer shape and orientation, etc.), the propulsion system may have any other suitable engine arrangement (e.g., an engine incorporated into a vertical stabilizer), any other suitable configuration, and so forth.

Referring now to FIG. 24, a cross-sectional view of a hypersonic propulsion engine 200 according to an exemplary aspect of the present disclosure is provided. The engine 200 provided in relation to fig. 24 is configured substantially similar to that shown and described in relation to fig. 1. It should be appreciated that the various embodiments of the engine 200 shown and described with respect to fig. 24 may be configured to include an RDC system 100 such as that shown and described with respect to fig. 1-22.

As will be appreciated, the depicted exemplary hypersonic propulsion engine 200 generally includes a turbine engine 202 and a bypass assembly 204. FIG. 24 provides a cross-sectional view of the entire length of the turbine engine 202 (with all of the duct assembly 204 shown). Notably, the hypersonic propulsion engine 200 may be incorporated into a hypersonic aircraft (such as the hypersonic aircraft 700 of FIG. 23 incorporated as the engine 102).

The depicted exemplary hypersonic propulsion engine 200 generally defines an engine inlet 208 at a forward end 211 along the longitudinal direction L and an engine exhaust port 213 at an aft end 215 along the longitudinal direction L. With reference to the exemplary turbine engine 202, it will be appreciated that the exemplary turbine engine 202 depicted defines a turbine engine inlet 217, which may be configured, for example, in accordance with the inlet 108 of FIG. 1. The turbine engine 202 further includes a turbine engine exhaust outlet 218, such as may be configured in accordance with the exhaust nozzle 135 of FIG. 1. Moreover, exemplary turbine engine 202 includes a compressor section, such as may be configured with respect to compressor section 104 of FIG. 1, a combustion section 205, and a turbine section, such as may be configured with respect to turbine section 106 of FIG. 1. The compressor section, combustion section 205, and turbine section are each arranged in a serial flow sequence with respect to one another. In various embodiments, the combustion section 205 may include an embodiment of the RDC system 100 such as shown and described with respect to fig. 1-22. Alternatively, combustion section 205 may include a detonation combustion system.

With respect to turbine engine 202, the compressor section may include a first compressor 220, the first compressor 220 having a plurality of sequential stages of compressor rotor blades (including a forward-most stage of compressor rotor blades). Similarly, the turbine section includes a first turbine 224, and further includes a second turbine 227. The first turbine 224 is a high speed turbine coupled to the first compressor 220 through a first engine shaft 229. In this manner, the first turbine 224 may drive the first compressor 220 of the compressor section. The second turbine 227 is a low speed turbine coupled to the second engine shaft 231.

As will also be appreciated, for the illustrated embodiment, the hypersonic propulsion engine 200 further includes a fan 232. The fan 232 is located forward (and upstream) of the turbine engine inlet 217. Further, fan 232 includes a fan shaft 234, and for the illustrated embodiment, fan shaft 234 is coupled to second engine shaft 231 or is integrally formed with second engine shaft 231 such that second turbine 227 of the turbine section of turbine engine 202 may drive fan 232 during operation of hypersonic propulsion engine 200. The engine 200 further includes a plurality of outlet guide vanes 233, for the depicted embodiment, the outlet guide vanes 233 are variable outlet guide vanes (which are configured to pivot about a rotational pitch axis (shown in phantom)). The variable outlet guide vanes may further act as struts. In any event, the variable outlet guide vanes 233 may enable the fan 232 to operate at variable speeds and still discharge a relatively straight flow of air. In other embodiments, the outlet guide vanes 233 may instead be fixed pitch guide vanes.

Still referring to FIG. 24, the bypass assembly 204 generally includes an outer casing 236 and defines a bypass duct 238, the outer casing 236 and the bypass duct 238 extending around the turbine engine 202. Bypass duct 238 may have a substantially annular shape extending around turbine engine 202, such as substantially 360 degrees around turbine engine 202. Additionally or alternatively, the enclosure 236 and/or the bypass duct 238 may at least partially define a two-dimensional cross-section (e.g., a rectangular cross-section) that defines a height and a width. Various embodiments of the housing 236 and/or bypass duct 238 may correspond to the RDC system 100 being an annular or two-dimensional configuration. It should be appreciated that, in various embodiments, the housing 236 and/or the bypass duct 238 may define an annular portion and a two-dimensional portion.

For the embodiment illustrated with respect to fig. 24, the bypass duct 238 extends between a bypass duct inlet 240 and a bypass duct exhaust 242. The bypass duct inlet 240 is aligned with the turbine engine inlet 217 for the illustrated embodiment and the bypass duct exhaust outlet 242 is aligned with the turbine engine exhaust outlet 218 for the illustrated embodiment.

Moreover, for the illustrated embodiment, the bypass assembly 204 further defines an inlet section 244 at least partially forward of the bypass duct 238 and an afterburner chamber 246 downstream of the bypass duct 238 and at least partially aft of the turbine engine exhaust 218. With particular reference to the inlet section 244, for the illustrated embodiment, the inlet section 244 is located forward of the bypass duct inlet 240 and the turbine engine inlet 217. Further, for the illustrated embodiment, the inlet section 244 extends from the hypersonic propulsion engine inlet 208 to the turbine engine inlet 217 and the bypass duct inlet 240. In contrast, afterburner 246 extends from bypass duct exhaust port 242 and turbine engine exhaust port 218 to high supersonic propulsion engine exhaust port 213 (FIG. 24).

Still referring to fig. 24, the depicted hypersonic propulsion engine 200 may further include an inlet precooler 248 positioned at least partially within the inlet section 244 of the duct assembly 204 and upstream of (and more particularly, for the illustrated embodiment, upstream of both the turbine engine inlet 217, the bypass duct 238, or both). An inlet precooler 248 is generally provided for cooling the airflow through the inlet section 244 of the duct assembly 204 to the turbine engine inlet 217, the bypass duct 238, or both.

During operation of the hypersonic propulsion engine 200, an inlet airflow is received through the hypersonic propulsion engine inlet 208. The inlet airflow passes through the inlet precooler 248, thereby reducing the temperature of the inlet airflow. The inlet airflow then flows into the fan 232. As will be appreciated, the fan 232 generally includes a plurality of fan blades 250 that are rotatable by the fan shaft 234 (and the second engine shaft 231). The rotation of the fan blades 250 of the fan 232 increases the pressure of the inlet airflow. For the illustrated embodiment, the hypersonic propulsion engine 200 further includes a stage one guide vane 252 located downstream of the plurality of fan blades 250 of the fan 232 and upstream of the turbine engine inlet 217 (and the bypass duct inlet 240). For the illustrated embodiment, the stage guide vanes 252 are stage one variable guide vanes, each rotatable about its respective axis. The guide vanes 252 may change the direction of inlet airflow from a plurality of fan blades 250 of the fan 232. A first portion of the inlet airflow flows from the stage guide vanes 252 through the turbine engine inlet 217 and along a core air flow path 254 of the turbine engine 202, and a second portion of the inlet airflow flows through the bypass duct 238 of the duct assembly 204, as will be explained in greater detail below. Briefly, it will be appreciated that the exemplary hypersonic propulsion engine 200 includes a forward frame including forward frame struts 256 (and more specifically, a plurality of circumferentially spaced forward frame struts 256), the forward frame struts 256 extending through the bypass duct 238 proximate the bypass duct inlet 240 and through the core air flow path 254 of the turbine engine 202 proximate the turbine engine inlet 217.

Generally, a first portion of air passes through first compressor 220, where the temperature and pressure of such first portion of air is increased and provided to combustion section 205. The combustion section 205 includes a plurality of fuel nozzles 258 spaced along the circumferential direction C for providing a mixture of an oxidant, such as compressed air, and a liquid and/or gaseous fuel to a combustion chamber (e.g., the detonation chamber 122) of the combustion section 205. In various embodiments, the plurality of fuel nozzles 258 of the engine 200 are arranged and configured in accordance with one or more embodiments of the plurality of fuel injectors 128 of the RDC system 100 shown and described herein.

The compressed air and fuel mixture is combusted to produce combustion gases, which are provided through the turbine section. The combustion gases expand across the first turbine 224 and the second turbine 227, driving the first turbine 224 (and the first compressor 220 via the first engine shaft 229) and the second turbine 227 (and the fan 232 via the second engine shaft 231). The combustion gases are then exhausted through the turbine engine exhaust port 218 and provided to the afterburner 246 of the bypass assembly 204.

As schematically depicted, the hypersonic propulsion engine 200, and in particular the turbine engine 202, includes a plurality of bearings 260 for supporting one or more rotating components of the hypersonic propulsion engine 200. For example, the depicted exemplary hypersonic propulsion engine 200/turbine engine 202 includes one or more bearings 260 supporting a first engine shaft 229 and a second engine shaft 231. For the illustrated embodiment, one or more of the bearings 260 are configured as air bearings. However, it will be appreciated that in other exemplary embodiments, one or more bearings 260 may be formed in any other suitable manner. For example, in other embodiments, one or more of the bearings 260 may be roller bearings, ball bearings, or the like.

Still referring to fig. 24, as noted above, the second portion of the inlet airflow is provided by the bypass duct 238. Notably, for the illustrated embodiment, the bypass duct 238 includes a dual flow section. The dual flow section includes an inner bypass flow 262 and an outer bypass flow 264. The inner and outer bypass flows 262, 264 are in a parallel flow configuration and, for the illustrated embodiment, extend at least partially outside of the first compressor 220 of the compressor section of the turbine engine 202. Notably, for the illustrated embodiment, the bypass assembly 204 includes an bypass damper 266 located at an upstream end of the bypass flow 264. The bypass flow gate 266 is movable between a closed position (shown) and an open position (depicted in phantom). When in the closed position, the outer bypass flow gate 266 substantially completely blocks the outer bypass flow 264 such that substantially all of the second portion of the inlet airflow received through the bypass duct 238 flows through the inner bypass flow 262. In contrast, when in the open position, the outer bypass damper 266 allows airflow through the outer bypass flow 264. Notably, the bypass assembly 204 is aerodynamically designed such that a ratio of an amount of airflow through the outer bypass flow 264 to an amount of airflow through the inner bypass flow 262 is greater than 1:1, such as greater than about 2:1, such as greater than about 4:1, and less than about 100:1, such as less than about 10:1, when the outer bypass damper 266 is in the open position under hypersonic flight operating conditions.

Still referring to the dual flow section, and more particularly to the inner bypass flow 262, it will be appreciated that for the illustrated embodiment, the bypass assembly 204 further includes a primary airfoil 268 positioned at least partially within the inner bypass flow 262. More specifically, for the illustrated embodiment, each of the compressor rotor blades 222 of the forward-most stage of the first compressor 220 of the turbine engine 202 defines a radially outer end. The stage airfoils 268 of the duct assembly 204 are coupled at radially outer ends to the leading stage of compressor rotor blades 222. In this manner, the stage airfoil 268 is configured to be driven by and rotate with the first compressor 220 during at least some operations. For the illustrated embodiment, this stage airfoil 268 of the duct assembly 204 is a stage compression airfoil configured to compress a second portion of the air flowing through the inner bypass duct flow 262, thereby increasing the pressure and/or flow rate of such air flow.

Downstream of the dual-flow section of the bypass duct 238, the second portion of the inlet airflow merges together and flows generally along the longitudinal direction L to the bypass duct exhaust 242. For the illustrated embodiment, the air flow through the bypass duct 238 merges with the exhaust gases of the turbine engine 202 at the afterburner 246. The depicted exemplary hypersonic propulsion engine 200 includes bypass airflow doors 270 at the turbine engine exhaust port 218 and the bypass exhaust port 242. The bypass airflow door 270 is movable between an open position (shown) in which airflow through the core air flow path 254 of the turbine engine 202 is free to flow into the afterburner chamber 246, and a closed position (shown in phantom) in which airflow from the bypass duct 238 is free to flow into the afterburner chamber 246. Notably, the bypass airflow door 270 may be further movable between various positions between the open and closed positions to allow a desired ratio of airflow from the turbine engine 202 into the afterburner chamber 246 to airflow from the bypass duct 238 into the afterburner chamber 246.

During certain operations, such as during hypersonic flight operations, further thrust may be achieved from the air flow into and through the afterburner chamber 246. More specifically, for the illustrated embodiment, the hypersonic propulsion engine 200 further includes an augmentor 272 positioned at least partially within the afterburner chamber 246. In particular, for the illustrated embodiment, the augmentor 272 is positioned at an upstream end of the afterburner chamber 246, and more particularly, immediately downstream of the bypass duct exhaust port 242 and the turbine engine exhaust port 218.

Notably, for the illustrated embodiment, the afterburner chamber 246 is configured as a deflagration chamber, and the augmentor 272 incorporates a rotary detonation combustor 274 (such as the embodiments of the RDC system 100 shown and described with respect to fig. 1-22). In a particular embodiment, intensifier 272 includes a plurality of fuel injectors 128, such that fuel injectors 128 are configured such as shown and described with respect to fig. 1-6. It should further be appreciated that embodiments of the afterburner chamber 246 may correspond at least in part to the detonation chamber 122 configured such as shown and described with respect to fig. 1-6.

Further, referring back to fig. 24, it will be appreciated that afterburner chamber 246 generally extends to the hypersonic propulsive engine exhaust port 213, thereby defining a nozzle outlet 282 at the hypersonic propulsive engine exhaust port 213. Further, the afterburner chamber 246 defines an afterburner axial length 284 between the turbine engine exhaust 218 and the hypersonic propulsion engine exhaust 213. In various embodiments, the afterburner axial length 284 corresponds to the detonation chamber length 123 of the RDC system 100 shown and described with respect to fig. 1-22. In a particular embodiment, the hypersonic propulsion engine exhaust 213 corresponds to the detonation chamber outlet 126 such as shown and described herein. Similarly, turbine engine 202 defines a turbine engine axial length 286 between turbine engine inlet 217 and turbine engine exhaust outlet 218. For the depicted embodiment, the afterburner axial length 284 is at least about fifty percent of the turbine engine axial length 286 and up to about five-hundred percent of the turbine engine axial length 286. More specifically, for the illustrated embodiment, the afterburner axial length 284 is greater than the turbine engine axial length 286. For example, in certain embodiments, the afterburner chamber 246 can define an afterburner axial length 284, with the afterburner axial length 284 being at least about 125% of the turbine engine axial length 286, such as at least about 150% of the turbine engine 202. However, in other embodiments (such as embodiments incorporating the rotary detonation combustor 274), the afterburner axial length 284 may be less than the turbine engine axial length 286.

Further, it will be appreciated that, in at least certain exemplary embodiments, the hypersonic propulsion engine 200 may include one or more components for varying the cross-sectional area of the nozzle outlet 282. As such, nozzle outlet 282 may be a variable geometry nozzle outlet configured to vary the cross-sectional area based on, for example, one or more flight operations, ambient conditions, or operating modes of RDC system 100 (e.g., to maintain rotational detonation of the fuel/oxidant mixture), etc.

For the illustrated embodiment, it will be appreciated that the exemplary hypersonic propulsion engine 200 further includes a fuel delivery system 288. Fuel delivery system 288 is configured to provide flowing fuel to combustion section 205 of turbine engine 202, and for the illustrated embodiment, augmentor 272 is positioned at least partially within afterburner chamber 246. An embodiment of the engine 200 includes a controller 210 such as that shown and described with respect to FIG. 1. The depicted exemplary fuel delivery system 288 generally includes a fuel tank 290 and a fuel oxygen reduction unit 292. The fuel oxygen reduction unit 292 may be configured to reduce the oxygen content of the fuel stream from the fuel tank 290 and through the fuel delivery system 288.

The fuel delivery system 288 further includes a fuel pump 264, the fuel pump 264 being configured to increase the pressure of the flow of fuel through the fuel delivery system 288. Further, for the illustrated embodiment, the inlet precooler 248 is a fuel-air heat exchanger that is thermally coupled to the fuel delivery system 288. More specifically, for the illustrated embodiment, the inlet precooler 248 is configured to directly utilize fuel as the heat exchange fluid such that heat extracted from the inlet airflow by the inlet section 244 of the bypass assembly 204 is transferred to the fuel flow through the fuel delivery system 288. For the illustrated embodiment, the heated fuel (which, as discussed above, may increase in temperature by an amount corresponding to the amount by which the inlet airflow temperature is reduced by the inlet precooler 248) is then provided to the combustion section 205 and/or the augmentor 272. It is worth noting that, in addition to acting as a relatively efficient radiator, increasing the temperature of the fuel prior to combustion may further increase the efficiency of the hypersonic propulsion engine 200.

In various embodiments, the fuel delivery system 288 is in operable communication with the controller 210 to receive and/or transmit data, commands, or feedback between each other. The fuel delivery system 288, the controller 210, and the RDC system 100, such as positioned at the combustion section 202 and/or the afterburner 236, may be in communication with and operably coupled to each other. In particular embodiments, the fuel delivery system 288 is configured to provide a flow rate, pressure, temperature, density, or other fuel flow characteristic to the fuel flow corresponding to the desired fuel/oxidant mixture from the fuel injector 128. The fuel delivery system 288 may further be in operable communication with the controller 210 to provide respective liquid and/or gaseous fuel streams to the RDC system 100, such as may be positioned at the combustion section 202 and/or the afterburner 236. In particular embodiments, the fuel delivery system 288 may provide the flow of fuel in thermal communication with the inlet precooler 248 based at least in part on the desired unidirectional pressure wave propagation corresponding to the sustaining detonation wave 130.

The embodiments illustrated and described with respect to fig. 1-24 may include elements, features, reference numbers, details, or methods of operation illustrated or described with respect to one figure, but not necessarily with respect to another figure. It should be further appreciated that one or more of the figures may omit certain features for clarity. Furthermore, for clarity, descriptions or depictions of elements, features, reference numbers, details, or methods of operation may be distributed across two or more figures. It should be appreciated that elements, features, reference numbers, details, or methods shown or described with respect to one figure may be applicable to any or all of the other figures provided herein, unless otherwise stated. As such, combinations of elements, features, reference numbers, details, or methods illustrated or described herein with respect to two or more figures may constitute embodiments within the scope of the present disclosure as if depicted together in a single figure.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Further aspects of the invention are provided by the subject matter of the following clauses:

1. a system for rotary detonation combustion, the system comprising an inner wall and an outer wall each extending about a centerline axis, wherein a detonation chamber is defined between the inner wall and the outer wall. The system includes an iterative structure positioned at one or both of the inner wall or the outer wall, wherein the iterative structure includes a first threshold structure corresponding to a first pressure wave attenuation and a second threshold structure corresponding to a second pressure wave attenuation. The iterative structure provides pressure wave intensification in a first circumferential direction in the detonation chamber, or provides pressure wave attenuation in a second circumferential direction opposite the first circumferential direction. The first circumferential direction corresponds to a desired direction of propagation of pressure waves in the detonation chamber.

2. The system of any preceding clause, wherein the iterative structure comprises an arcuate portion, the arcuate portion comprising a first threshold structure and a second threshold structure.

3. The system of any preceding clause, wherein the iterative structure comprises a waveform extending in a radial direction from one or more of the inner wall or the outer wall.

4. The system of any preceding clause, wherein the iterative structure comprising the waveform further comprises a first wall and a second wall that together define a ramp structure extending along a circumferential direction in the detonation chamber, the ramp structure extending radially from one or more of the inner wall or the outer wall.

5. The system of any preceding clause, wherein the waveform comprises one or more of a triangular wave, a square wave, a sawtooth wave, a sine wave, or a combination thereof.

6. The system according to any preceding clause, wherein the second wall extends at least partially tangentially or substantially tangentially from the first wall to an inner or outer wall to which the first wall is connected.

7. The system according to any preceding clause, wherein the second wall extends from the first wall at the first radial height in a concave, convex, or sinusoidal fashion to the inner or outer wall to which the first wall is connected.

8. The system of any preceding clause, wherein the iterative structure comprises two or more arcuate portions at the detonation chamber, wherein each arcuate portion of the iterative structure comprises: a radial wall extending from one or more of the inner wall or the outer wall to a first radial height; and a second wall extending from a first radial height at the radial wall to the inner or outer wall to which the radial wall is connected.

9. The system according to any preceding clause, wherein the second wall extends from the radial wall along a desired direction of propagation of pressure waves in the detonation chamber.

10. The system according to any preceding clause, wherein the first radial height is between 3% and 50% of a flow path height, wherein the flow path height extends from the inner wall to the outer wall.

11. The system according to any preceding clause, wherein the first radial height is between 3% and 25% of a flow path height, wherein the flow path height extends from the inner wall to the outer wall.

12. The system according to any preceding clause, wherein the second wall extends at least partially tangentially from the first wall to an inner or outer wall to which the first wall is connected.

13. The system according to any preceding clause, wherein the system iteration structure comprises two or more arcuate portions arranged circumferentially in the detonation chamber.

14. The system of any preceding clause, wherein the system comprises between two and two hundred arcuate sections of the iterative structure arranged circumferentially in the detonation chamber.

15. The system of any preceding clause, wherein the iterative structure comprises: a first radial wall extending from one or more of the inner wall or the outer wall to a first radial height; a second radial wall extending from one or more of the inner wall or the outer wall to a second radial height less than the first radial height; a first sloped wall extending from a first radial height at the first radial wall to an inner or outer wall from which the first radial wall extends; and a second sloped wall extending from a second radial height at the second radial wall to the inner or outer wall from which the second radial wall extends.

16. The system according to any preceding clause, wherein the first sloped wall and the second sloped wall each extend to the inner wall or the outer wall along a desired direction of propagation of the pressure wave.

17. The system of any preceding clause, further comprising a fuel injector extending along the longitudinal direction, wherein the fuel injector outlet is positioned in a region between the second wall and the first wall.

18. The system of any preceding clause, wherein the fuel injector outlet is positioned between an inner or outer wall from which the first wall extends and a first radial height of the first wall.

19. The system of any preceding clause, wherein the fuel injector outlet is positioned upstream of the ramp structure.

20. The system of any preceding clause, wherein the fuel injector is positioned at a substantially tangential angle relative to a detonation path in the detonation chamber.

21. The system according to any preceding clause, wherein the angle is between 0 degrees and 90 degrees toward the desired direction of pressure wave propagation.

22. The system of any preceding clause, wherein the iterative structure includes a plurality of fuel injectors each extending along the longitudinal direction.

23. The system of any preceding clause, wherein the plurality of fuel injectors each extend in a tangential direction toward the desired direction of propagation of the pressure wave.

24. The system of any preceding clause, wherein the plurality of fuel injectors each comprise a converging-diverging nozzle.

25. The system of any preceding clause, wherein the plurality of fuel injectors each include a fuel injector outer wall configured to produce a coanda effect of a flow of fuel from the converging-diverging nozzle to the detonation chamber.

26. The system of any preceding clause, wherein the plurality of fuel injectors each comprise a fuel injector outer wall comprising a longitudinal portion defining a fuel passage and a wall angled relative to a fuel injector centerline axis, wherein an angle of the angled wall corresponds to the emission coefficient.

27. The system according to any preceding clause, wherein the angled wall is angled between 0 degrees and 90 degrees.

28. The system according to any preceding clause, wherein the plurality of fuel injectors are arranged in an order in which the emission coefficient increases along the desired direction of propagation of the pressure wave.

29. The system of any preceding clause, wherein the plurality of fuel injectors includes a minimum emission coefficient fuel injector and a maximum emission coefficient fuel injector, wherein the minimum emission coefficient fuel injector is positioned sequentially circumferentially after the maximum emission coefficient fuel injector.

30. The system of any preceding clause, wherein the iterative structure comprises two or more fuel injectors, wherein each of the plurality of fuel injectors comprises a fuel injector of maximum emission coefficient sequentially following a fuel injector of minimum emission coefficient along the desired direction of propagation of the pressure wave.

31. The system of any preceding clause, wherein the iterative structure further comprises one or more intermediate emission coefficient fuel injectors positioned between the minimum emission coefficient fuel injector and the maximum emission coefficient fuel injector.

32. The system of any preceding clause, wherein the change in emission coefficient from the fuel injector of the minimum emission coefficient to the fuel injector of the maximum emission coefficient is between a multiple of 2 and a multiple of 3.

33. The system of any preceding clause, wherein the system comprises between two and forty iterative structures in a circumferential arrangement, wherein the iterative structures are arranged in repeating arcs along the desired direction of pressure propagation.

34. The system of any preceding clause wherein the repeating arc of the iterative structure is between a 9 degree arc and a 180 degree arc.

35. The system according to any preceding clause, wherein the iterative structure comprises a plurality of dampers arranged in an order that the target pressure decay frequency increases or decreases.

36. The system of any preceding clause, wherein the plurality of dampers includes a minimum attenuation target damper and a maximum attenuation target damper, wherein the minimum attenuation target damper is positioned sequentially circumferentially after the maximum attenuation target damper.

37. The system according to any preceding clause, wherein the iterative structure comprises two or more dampers, wherein each of the plurality of dampers comprises a maximum attenuation target damper sequentially following a minimum attenuation target damper along the desired direction of pressure wave propagation.

38. The system of any preceding clause, wherein the iterative structure further comprises one or more intermediate attenuation target dampers positioned between the minimum attenuation target damper and the maximum attenuation target damper.

39. The system of any preceding clause, wherein the system comprises between two and forty arcuate sections of the iterative structure in a circumferential arrangement, wherein the iterative structure is arranged in a repeating arc along the desired direction of pressure propagation.

40. The system of any preceding clause wherein the repeating arc of the iterative structure is between a 9 degree arc and a 180 degree arc.

41. The system according to any preceding clause, wherein the plurality of dampers each define a helmholtz adapter configured to determine the target frequency based at least on a desired attenuation of the pressure wave relative to a desired direction of propagation of the pressure wave.

42. The system of any preceding clause, comprising a plurality of fuel injectors, wherein the damper comprises a fuel cavity from which fuel flow is provided to two or more of the plurality of fuel injectors.

43. The system according to any preceding clause, wherein the plurality of dampers are arranged in a sequential arrangement and are configured to increase pressure frequency attenuation relative to a desired direction of pressure wave propagation.

44. The system according to any preceding clause, wherein the minimal attenuation damper is positioned circumferentially adjacent to the pre-detonation device relative to the desired direction of pressure wave propagation.

45. The system of any preceding clause, comprising a first fuel circuit configured to provide a flow of fuel to a first fuel nozzle, wherein the first fuel circuit is fluidly coupled to a first damper, and wherein the system comprises a second fuel circuit configured to provide a flow of fuel to a second fuel nozzle, wherein the second fuel nozzle is circumferentially adjacent to the first fuel nozzle along the desired direction of pressure propagation, and wherein the second fuel circuit is fluidly coupled to a second damper.

46. The system of any preceding clause, wherein the first damper is configured to have a pressure frequency attenuation less than the second damper.

47. The system of any preceding clause, wherein the iterative structure comprises one or more of a fuel nozzle, a fuel injector, a damper, a ramp structure, or a fuel circuit, or a combination thereof.

48. A heat engine comprising a system according to any preceding clause.

49. A turbine comprising a system according to any preceding clause.

50. A hypersonic propulsion system comprising a system according to any preceding clause.

51. A vehicle comprising a system according to any preceding clause.