阅读说明：本技术 一种用于冲压发动机含颗粒凝胶推进剂雾化的自激振荡喷嘴 (Self-oscillation nozzle for atomizing granular gel-containing propellant of ramjet engine ) 是由 富庆飞 杨立军 贾伯琦 于 2019-09-09 设计创作，主要内容包括：本发明公开了一种用于冲压发动机含颗粒凝胶推进剂雾化的自激振荡喷嘴,包括上下连接的喷嘴入口和喷嘴出口,其中,喷嘴入口的内部包括由上到下相互连通的液体入口、入口喷口和共振腔,液体入口和共振腔的型面为圆柱形,入口喷口的型面为圆柱形或者上部收敛锥形加下部圆柱形；喷嘴出口的内部包括由上到下相互连通的装配口和出口喷口,装配口和出口喷口的型面均为圆柱形,装配口用于实现喷嘴入口与喷嘴出口的连接；入口喷口和出口喷口的直径小于共振腔的直径。本发明结构简单、操作方便、尺寸小、易于拆装维护、可靠性高、雾化效果优良、能够明显提高燃烧效率,能够良好适应超燃冲压发动机高温高压工况。(The invention discloses a self-oscillation nozzle for atomizing a particle-containing gel propellant of a ramjet engine, which comprises a nozzle inlet and a nozzle outlet which are connected up and down, wherein the inside of the nozzle inlet comprises a liquid inlet, an inlet nozzle and a resonant cavity which are communicated with each other from top to bottom; the inner part of the nozzle outlet comprises an assembly opening and an outlet spout which are communicated with each other from top to bottom, the molded surfaces of the assembly opening and the outlet spout are cylindrical, and the assembly opening is used for realizing the connection between the nozzle inlet and the nozzle outlet; the diameter of the inlet and outlet jets is less than the diameter of the resonant cavity. The invention has the advantages of simple structure, convenient operation, small size, easy disassembly and assembly and maintenance, high reliability and excellent atomization effect, can obviously improve the combustion efficiency and can well adapt to the high-temperature and high-pressure working condition of the scramjet engine.)

1. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine, comprising a nozzle inlet and a nozzle outlet connected one above the other, wherein,

the inner part of the nozzle inlet comprises a liquid inlet, an inlet spout and a resonant cavity which are communicated with each other from top to bottom, the profiles of the liquid inlet and the resonant cavity are cylindrical, and the profile of the inlet spout is cylindrical or the upper part is convergent cone and the lower part is cylindrical;

the nozzle outlet comprises an assembly opening and an outlet spout which are communicated from top to bottom, the profiles of the assembly opening and the outlet spout are both cylindrical, and the assembly opening is used for realizing the connection between the nozzle inlet and the nozzle outlet;

the diameter of the inlet jet and the outlet jet is smaller than the diameter of the resonance chamber.

2. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine as set forth in claim 1, wherein: the upper part of the outer profile of the nozzle inlet is provided with an inlet first external thread, the middle part of the outer profile of the nozzle inlet is provided with an inlet sealing cylindrical surface, the lower part of the outer profile of the nozzle inlet is provided with an inlet second external thread, the outer diameters of the inlet sealing cylindrical surfaces are smaller than those of the inlet first external thread and the inlet second external thread, the inlet first external thread is used for being connected with an external propellant supply system, the inlet second external thread is used for being connected with the nozzle outlet, the bottom of the nozzle inlet is further extended with an inlet outer bottom pillar along the axial direction of the nozzle inlet, the outer diameter of the inlet outer bottom pillar is smaller than that of the inlet second external thread, the side surface of the inlet outer bottom pillar is a bottom cylindrical surface, and the bottom end surface of the inlet outer bottom; the top of nozzle entry is equipped with the straight groove, the straight groove can cooperate the instrument to realize the fastening of nozzle entry with the nozzle export.

3. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine as set forth in claim 2, wherein: an outlet external thread is arranged on the outer profile surface of the nozzle outlet and is used for being connected with an external propellant supply system II, an outlet outer bottom column also extends from the bottom of the nozzle outlet along the axial direction of the nozzle outlet, the outer diameter of the outlet outer bottom column is smaller than that of the outlet external thread, the side surface of the outlet outer bottom column is a step cylindrical surface, and the surface which is positioned above the step cylindrical surface and is vertically connected with the step cylindrical surface is a step end surface; and a fastening plane is arranged between the step cylindrical surface and the outlet external thread and can be matched with a tool to realize the fastening of the nozzle outlet and the nozzle inlet.

4. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine according to claim 2 or 3, wherein: the outer end face of the top of the nozzle outlet is a plane; the profile of the assembly port comprises an outlet sealing cylindrical surface, after the nozzle inlet is connected with the nozzle outlet, the outlet sealing cylindrical surface is opposite to the inlet sealing cylindrical surface, and the outlet sealing cylindrical surface and the inlet sealing cylindrical surface are filled and sealed by an O-shaped sealing ring; the outlet nozzle is positioned in the middle of the inner bottom end surface, and after the nozzle inlet is connected with the nozzle outlet, the outlet nozzle is communicated with the resonant cavity up and down.

5. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine according to claim 4, wherein: the outer end face of the top of the nozzle outlet is a sealing end face, after the propellant supply system fixes the nozzle inlet through the first external thread of the inlet, a first gasket is required to be arranged between the bottom of the propellant supply system and the sealing end face so as to realize the sealing between the nozzle inlet and the propellant supply system; after the propellant supply system II fixes the nozzle outlet through the outlet external thread, a gasket II is required to be arranged between the bottom of the propellant supply system II and the step cylindrical surface and between the bottom of the propellant supply system II and the step end surface, so that the nozzle outlet is sealed with the propellant supply system II.

6. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine as set forth in claim 2, wherein: the diameter range of the liquid inlet is 1.5-3mm, and the length-diameter ratio range is 1-3; the diameter range of the inlet outer bottom column is 1.5-5mm, and the length of the cylindrical surface is 0.5-2 mm.

7. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine as set forth in claim 1, wherein: when the profile of the inlet nozzle is cylindrical, the diameter of the cylinder is in the range of 0.4-0.7mm, and the length-diameter ratio is in the range of 0.5-3.

8. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine as set forth in claim 1, wherein: when the profile of the inlet nozzle is an upper convergent cone and a lower cylinder, the convergent angle range of the convergent cone is 20-150 degrees, the diameter range of the cylinder is 0.4-0.7mm, and the length-diameter ratio range of the cylinder is 0.2-1.

9. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine as set forth in claim 1, wherein: the diameter range of the resonant cavity is 1-4mm, the length-diameter ratio range is 0.8-2, and the ratio of the diameter of the resonant cavity to the diameter of the inlet nozzle ranges from 2.5-6.

10. A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine as set forth in claim 1, wherein: the diameter range of the outlet nozzle is 0.42-0.85mm, the length-diameter ratio range is 0.5-3, and the diameter ratio of the outlet nozzle to the inlet nozzle ranges from 1-1.2.

Technical Field

The invention relates to a self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine. The injector is mainly applied to injectors of thrust chambers of ramjets and rocket engines.

Background

The light metal particles with high heat value are used as high-energy fuel, and have wide application prospect in the field of aerospace propellants. Its advantages are high heat value, and high density and combustion temp of propellant, resulting in high specific impact of engine. Furthermore, certain types of metal particles contribute to the stable combustion of the propellant. However, the propellant containing metal particles has a very high viscosity, even shows non-newtonian fluid properties, and is atomized by using a conventional nozzle (a direct current nozzle, a pneumatic atomizing nozzle, a centrifugal nozzle, etc.), which may face the problems of insufficient atomization fineness, particle sedimentation, nozzle blockage, etc. Accordingly, there is a need to develop new nozzles for the efficient atomization of propellant containing particles.

The self-excited oscillation nozzle is a nozzle structure which amplifies jet disturbance energy, accelerates processes of jet instability, cavitation and the like and further generates oscillation jet. The excitation principle comprises the theories of fluid stability, fluid resonance, water acoustics and the like. According to the jet stability theory, jet instability at the outlet of the direct-current nozzle is in a specific frequency and wavelength range, and the jet fracture wavelength can be controlled by adjusting the frequency of disturbance waves, namely controlling the frequency of jet instability. And the capillary wave theory considers that the reduction of the surface wavelength is beneficial to improving the atomization fineness. Both experimental and theoretical results demonstrate that surface wavelength can be effectively reduced by increasing the perturbation frequency. The better disturbance frequency is determined by parameters such as jet diameter, speed and the like, an oscillation cavity with a specific size is designed by utilizing a self-oscillation principle, self-oscillation with specific frequency is generated, and instability of jet flow under the frequency is excited, so that the atomization effect is improved. The traditional self-excited oscillation jet nozzle, such as a multifunctional self-excited oscillation abrasive water jet generator announced by CN 102133562A, a high-pressure water jet self-excited oscillation nozzle device announced by CN203711178U, a high-pressure self-excited oscillation pulse jet nozzle with continuously adjustable cavity length announced by CN103817028, a self-excited oscillation pulse jet nozzle announced by CN203961086U and the like, has larger or more complex structural size, is difficult to be applied to the aerospace field, especially to a stamping engine with the requirement on the diameter of a nozzle port being less than 0.6mm, and is difficult to carry out complex processing on the inner profile of the stamping engine under the condition of ensuring the precision; although the impulse jet nozzle disclosed in CN 204571851U, the oscillation impulse jet nozzle disclosed in CN2054479U for the dental bed drill bit, the oscillation impulse jet nozzle disclosed in CN2699997Y and the jet generator of the self-oscillation cavitation structure disclosed in CN 2124339 have small structural size, the inner molded surface is complex, and when the diameter of the jet is less than 0.6mm, the jet generator is difficult to process, even adopts integral forming, is very unfavorable for the processes of structural detection in the previous stage and the like, and leaves hidden troubles for reliable combustion. In addition to this, the same problem exists with the above-mentioned nozzles, which are adapted in size to produce oscillating jets with high penetration, rather than to increase the fineness of atomization, and which are designed for the opposite purpose of the invention, and therefore have quite different structural size requirements. The self-oscillation jet impact type nozzle for complex fluid atomization disclosed in CN102019236A and the self-oscillation jet impact type nozzle with a conical reflecting surface resonant cavity disclosed in CN102161020A are designed to improve the atomization effect of an impact liquid film, so that the jet penetration force is stronger and the self-oscillation jet impact type nozzle is not suitable for an injector of a ramjet engine.

Therefore, how to provide a self-oscillation nozzle with a resonant cavity, which can improve the atomization effect of the gel propellant containing particles and improve the combustion efficiency and specific impulse of the ramjet engine, is an important research topic of the technicians in the field.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the above-mentioned problems in the prior art.

To this end, the invention proposes a self-oscillating nozzle for atomizing propellant containing particulate gel for ramjet engines, comprising a nozzle inlet and a nozzle outlet connected one above the other, wherein,

the inner part of the nozzle inlet comprises a liquid inlet, an inlet spout and a resonant cavity which are communicated with each other from top to bottom, the profiles of the liquid inlet and the resonant cavity are cylindrical, and the profile of the inlet spout is cylindrical or the upper part is convergent cone and the lower part is cylindrical;

the nozzle outlet comprises an assembly opening and an outlet spout which are communicated from top to bottom, the profiles of the assembly opening and the outlet spout are both cylindrical, and the assembly opening is used for realizing the connection between the nozzle inlet and the nozzle outlet;

the diameter of the inlet jet and the outlet jet is smaller than the diameter of the resonance chamber.

The invention relates to a self-oscillation nozzle for atomizing a propellant containing granular gel for a ramjet engine, which comprises the following specific working processes and working principles:

propellant enters the inlet nozzle from the liquid inlet, enters the resonance chamber through the inlet nozzle, and reaches the outlet nozzle. When liquid flows into the resonant cavity from the inlet nozzle, the flow passage area is widened, momentum exchange is carried out between gas in the cavity and jet flow, a shear layer with a certain thickness is formed, the shear layer is unstable to generate vortex, the jet flow carries the vortex to flow downstream, when the vortex reaches a downstream collision wall (namely the inner bottom end face of the nozzle outlet), a certain frequency disturbance pressure wave is generated, the frequency of the pressure wave is related to the diameter and the length of the resonant cavity, the pressure wave is reflected to the upstream, and when the pressure wave and the jet flow are in the same phase, the oscillation is superposed and amplified. This process is repeated and self-oscillation occurs. The jet flows out through the outlet nozzle, and instability of the jet can be enhanced in an unstable frequency range, so that atomization of the jet is enhanced; when the frequency value generated by the self-oscillation is within the unstable frequency range of the outlet jet flow, the instability of the outlet jet flow is amplified, and when the self-oscillation frequency is in a larger value in the unstable frequency range, the smaller wavelength disturbance is amplified and broken under the action of aerodynamic force and surface tension, so that liquid drops with smaller average size are generated, and the atomization effect is improved.

Therefore, the nozzle can achieve a better atomization effect under lower pressure, and can ensure enough penetration depth at the same time, thereby improving the combustion efficiency and specific impulse of the ramjet, and the nozzle has simple structure and strong reliability.

On the basis of the technical scheme, the invention can be improved as follows:

preferably, an inlet first external thread is arranged on the upper portion of the outer profile of the nozzle inlet, an inlet sealing cylindrical surface is arranged in the middle of the outer profile of the nozzle inlet, an inlet second external thread is arranged on the lower portion of the outer profile of the nozzle inlet, the outer diameters of the inlet sealing cylindrical surfaces are both smaller than the outer diameters of the inlet first external thread and the inlet second external thread, the inlet first external thread is used for being connected with an external propellant supply system, the inlet second external thread is used for being connected with the nozzle outlet, an inlet outer bottom column further extends from the bottom of the nozzle inlet along the axial direction of the nozzle inlet, the outer diameter of the inlet outer bottom column is smaller than the outer diameter of the inlet second external thread, the side surface of the inlet outer bottom column is a bottom cylindrical surface, and the bottom end surface of the inlet; the top of nozzle entry is equipped with the straight groove, the straight groove can cooperate the instrument to realize the fastening of nozzle entry with the nozzle export.

Preferably, an outlet external thread is arranged on the outer profile surface of the nozzle outlet and is used for being connected with an external propellant supply system II, an outlet outer bottom column also extends from the bottom of the nozzle outlet along the axial direction of the nozzle outlet, the outer diameter of the outlet outer bottom column is smaller than that of the outlet external thread, the side surface of the outlet outer bottom column is a step cylindrical surface, and the surface which is positioned above the step cylindrical surface and is vertically connected with the step cylindrical surface is a step end surface; and a fastening plane is arranged between the step cylindrical surface and the outlet external thread and can be matched with a tool to realize the fastening of the nozzle outlet and the nozzle inlet.

Preferably, the outer end face of the top of the nozzle outlet is a plane; the profile of the assembly port comprises an outlet sealing cylindrical surface, after the nozzle inlet is connected with the nozzle outlet, the outlet sealing cylindrical surface is opposite to the inlet sealing cylindrical surface in position and is filled and sealed by an O-shaped sealing ring, an outlet internal thread (M6 internal thread) matched with the second external thread of the inlet is arranged on the profile of the lower part of the outlet sealing cylindrical surface, the lower part of the outlet internal thread is an outlet inner bottom column matched with the inlet outer bottom column, the side surface of the outlet inner bottom column is an inner bottom cylindrical surface, the bottom of the outlet inner bottom column is an inner bottom end surface, the inner bottom cylindrical surface is matched and abutted with the bottom cylindrical surface, and the inner bottom end surface is matched and abutted with the bottom end surface; the outlet nozzle is positioned in the middle of the inner bottom end surface, and after the nozzle inlet is connected with the nozzle outlet, the outlet nozzle is communicated with the resonant cavity up and down.

The nozzle inlet and the nozzle outlet are preferably in threaded connection and sealed by O-shaped sealing rings, and are axially and radially positioned with the inner bottom cylindrical surface and the inner bottom end surface of the inner bottom column of the outlet through the bottom cylindrical surface and the bottom end surface of the outer bottom column of the inlet.

Preferably, the outer end face of the top of the nozzle outlet is a sealing end face, after the propellant supply system fixes the nozzle inlet through the first external thread of the inlet, a first gasket is required to be arranged between the bottom of the propellant supply system and the sealing end face to realize the sealing between the nozzle inlet and the propellant supply system; after the propellant supply system II fixes the nozzle outlet through the outlet external thread, a gasket II is required to be arranged between the bottom of the propellant supply system II and the step cylindrical surface and between the bottom of the propellant supply system II and the step end surface, so that the nozzle outlet is sealed with the propellant supply system II.

The top outer end face of the nozzle outlet is fitted with a gasket for sealing when the inlet first external thread is used for connecting to a propellant supply system.

When the outlet external thread is used for connecting a second propellant supply system, the stepped cylindrical surface of the outlet outer bottom column is used for radial positioning, and the stepped end surface of the outlet outer bottom column is matched with a second gasket for sealing.

Preferably, the liquid inlet has a diameter in the range of 1.5-3mm and an aspect ratio in the range of 1-3; the diameter range of the inlet outer bottom column is 1.5-5mm, and the length of the cylindrical surface is 0.5-2 mm.

Preferably, when the profile of the inlet nozzle is cylindrical, the diameter of the cylinder is in the range of 0.4 to 0.7mm and the aspect ratio is in the range of 0.5 to 3.

Preferably, when the profile of the inlet nozzle is an upper convergent cone plus a lower cylinder, the convergent angle of the convergent cone is in the range of 20 ° to 150 °, the diameter of the cylinder is in the range of 0.4 to 0.7mm, and the length-diameter ratio of the cylinder is in the range of 0.2 to 1.

Preferably, the diameter of the resonance cavity is in the range of 1-4mm, the length-diameter ratio is in the range of 0.8-2, and the ratio of the diameter of the resonance cavity to the diameter of the inlet nozzle is in the range of 2.5-6.

Preferably, the diameter of the outlet orifice ranges from 0.42 to 0.85mm, the aspect ratio ranges from 0.5 to 3, and the ratio of the diameter of the outlet orifice to the diameter of the inlet orifice ranges from 1 to 1.2.

The self-oscillation jet flow can be better formed by the design of the proportions.

Compared with the prior art, the self-oscillation nozzle for atomizing the propellant containing the particle gel of the ramjet engine has the advantages and effects that: under the condition of ensuring the penetration depth, the atomization effect is improved, and the atomization device is simple in structure, small in size, light in weight, strong in reliability and convenient to maintain.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

FIG. 1 is a schematic view showing a connection structure of a self-oscillation nozzle in embodiment 1 of the present invention;

FIG. 2 is a schematic view showing a connection structure of a self-oscillation nozzle in embodiment 2 of the present invention;

FIG. 3 is a schematic view showing the internal structure of a nozzle inlet in example 1 of the present invention;

FIG. 4 is a schematic view showing an external structure of an inlet of a nozzle in embodiment 1 of the present invention;

FIG. 5 is a top view of the nozzle inlet in example 1 of the present invention;

FIG. 6 is a schematic view showing the internal structure of a nozzle inlet in example 2 of the present invention;

FIG. 7 is a schematic view showing the internal structure of the nozzle outlet in examples 1 and 2 of the present invention;

FIG. 8 is a schematic view showing the external structure of the nozzle outlet in examples 1 and 2 of the present invention;

FIG. 9 is a top view of the nozzle outlet in examples 1 and 2 of the present invention;

FIG. 10 is a graph showing the comparison of atomization effect of the self-oscillating nozzle and the DC nozzle of the present invention;

wherein, in the figure,

100-the inlet of the nozzle-the nozzle,

101-liquid inlet, 102-inlet spout, 103-resonance chamber, 104-bottom cylindrical surface, 105-bottom end surface, 106-inlet sealing cylindrical surface, 107-inlet second external thread, 108-inlet first external thread, 109-straight groove;

200-the outlet of the nozzle-the nozzle,

201-outlet nozzle, 202-inner bottom end surface, 203-inner cylindrical surface, 204-outlet external thread, 205-outlet internal thread, 206-outlet sealing cylindrical surface, 207-fastening plane, 208-step end surface, 209-step cylindrical surface and 210-sealing end surface;

300-O type sealing ring;

400-spacer one;

500-propellant supply system;

600-spacer two;

700-propellant supply system two.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

A self-oscillating nozzle for atomizing a propellant containing particulate gel for a ramjet engine according to an embodiment of the present invention is described in detail below with reference to fig. 1-10.