阅读说明：本技术 一种前体带有预喷注的定几何二元高超声速进气道 (Fixed-geometry binary hypersonic inlet with pre-injection at precursor ) 是由 谢旅荣 王润洲 赵彬倩 胡蓉 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种前体带有预喷注的二元高超声速进气道,在前体压缩面上所设置后台阶面；后台阶上间隔设置的超声速气体喷注狭缝；台阶后端面设置两道面法线方向平行的射流狭缝用于燃料以及阻燃气体的喷注。所喷注的燃料沿着进气道内通道流动并逐渐与进气道捕获的主流进行掺混。而阻燃气体的喷注可以隔离燃料与进气道壁面的接触,防止燃料空气混合物在进气道内提前点燃,并有助于调节进气道出口的氢气分布情况。此外,当两种气体喷注的流量恰当时,在设计点状态下气体喷注对进气道前体波系结构影响较小,保证了进气道捕获流量的稳定。(The invention discloses a binary hypersonic inlet channel with a pre-injection in a precursor, wherein a rear step surface is arranged on a compression surface of the precursor; supersonic gas injection slits are arranged on the rear step at intervals; and the rear end surface of the step is provided with two jet slits parallel to the normal direction of the surface for jetting fuel and flame retardant gas. The injected fuel flows along the intra-port passage and gradually blends with the main flow captured by the port. And the injection of the flame-retardant gas can isolate the contact of fuel and the wall surface of the air inlet, prevent the fuel-air mixture from being ignited in the air inlet in advance and help to adjust the hydrogen distribution condition at the outlet of the air inlet. In addition, when the flow rates of the two gas injection are proper, the gas injection has small influence on the wave system structure of the front body of the air inlet channel in the state of a design point, and the stability of the capture flow rate of the air inlet channel is ensured.)

1. A fixed-geometry binary hypersonic inlet with a pre-injection in a precursor comprises an inner wall surface of the inlet, a lip cover positioned on the inner wall surface of the inlet, and a precursor compression surface extending forwards from the inner wall surface; the inner wall surface of the air inlet channel and the lip cover jointly form an inner channel of the air inlet channel; the compression surface of the front body is provided with a step part, and the step part forms a step surface with a height difference and faces backwards to the inner channel of the air inlet channel; a high-pressure fuel cavity and a high-pressure flame-retardant gas cavity are arranged in the precursor compression surface; the step part is provided with a fuel injection port and a flame-retardant gas injection port; the fuel injection port is communicated with the high-pressure fuel cavity, and the flame-retardant gas injection port is communicated with the high-pressure flame-retardant gas cavity.

2. The fixed geometry binary hypersonic inlet of claim 1, wherein said fuel injection port is located above a flame retardant gas injection port.

3. The fixed-geometry binary hypersonic inlet channel as claimed in claim 1 or 2, wherein the precursor compression surface comprises a primary compression wedge surface and a secondary compression surface which are sequentially extended and arranged backwards, and the front end of the secondary compression surface and the primary compression surface form a turning point; the rear end of the second-stage compression surface is connected with the inner wall surface of the air inlet channel, and the step part is positioned on the second-stage compression surface; the second-stage compression surface is stepped to form a front section and a rear section which are not collinear but parallel; the back step surface is vertical to the second stage compression surface of the front section and the second stage compression surface of the back section.

4. The fixed-geometry binary hypersonic inlet duct of claim 3, wherein the back step surface is at least 100mm from the compression surface inflection point.

5. The fixed-geometry binary hypersonic inlet duct of claim 4, wherein the back step surface is 300mm from the compression surface inflection point.

6. The fixed-geometry binary hypersonic inlet port of claim 5, wherein said flame retardant gas injection flow rate is 1.177 kg/s.

7. The fixed-geometry binary hypersonic inlet port of claim 3, wherein said fuel is hydrogen; the high pressure flame retardant gas is nitrogen.

8. The fixed-geometry binary hypersonic inlet port of claim 7, wherein both said fuel and flame-retardant gas injection ports are slots; the surface normal directions of the fuel injection port and the flame-retardant gas injection port are both parallel to the surface normal direction of the back step surface.

9. The fixed-geometry binary hypersonic air scoop of claim 1, wherein said interior wall surface is a surface of the air scoop disposed proximate to an exterior surface of the aircraft fuselage.

10. The fixed geometry binary hypersonic inlet duct of claim 1, wherein the step surface is spaced from an inlet of the passage in the inlet duct by an end distance.

Technical Field

The invention belongs to the technical field of aircraft air inlet channels.

Background

At present, in order to realize hypersonic flight, a thrust device used by an aircraft can be mainly divided into a rocket engine and an air suction type ramjet engine. The rocket engine is suitable for space exploration because the rocket engine does not depend on oxygen in the atmosphere, but if the rocket engine works in the atmosphere completely, the load is increased and a certain range is lost because a solid oxidant is carried. The ramjet uses oxygen in the air to participate in combustion, does not need to carry an oxidant, and has more remarkable advantages in the aspects of performance and thrust compared with a rocket engine when flying at supersonic speed. The hypersonic ramjet can be divided into two realization forms of a scrajet and a shock wave induced ramjet. For scramjet engines, since the fuel is in the combustion chamber for an extremely short time, in the order of ms, the fuel and the incoming air are optimally mixed in a chemically correct ratio to a molecular level in order to ensure ignition and stable combustion of the fuel. For shock wave induced combustion ramjet engines, the fuel also needs to be thoroughly mixed with the incoming air in advance to ensure ideal ignition and immobilization.

Therefore, the fuel is fully mixed with the main stream air before reaching the combustion chamber, and the key point of stable and efficient combustion of the combustion chamber of the hypersonic aircraft is realized. How to better enable the fuel to be fully mixed with the main flow air before reaching the combustion chamber is a technical problem to be solved urgently in the field of air inlet channel development.

Disclosure of Invention

The invention provides a fixed-geometry binary hypersonic inlet channel with a pre-injection precursor, and aims to provide a uniformly mixed combustible mixture for a scramjet combustor.

In order to achieve the purpose, the invention provides the following scheme:

a fixed-geometry binary hypersonic inlet with a pre-injection in a precursor comprises an inner wall surface of the inlet, a lip cover positioned on the inner wall surface of the inlet, and a precursor compression surface extending forwards from the inner wall surface; the inner wall surface of the air inlet channel and the lip cover jointly form an inner channel of the air inlet channel; the compression surface of the front body is provided with a step part, and the step part forms a step with a height difference and faces backwards to the inner channel of the air inlet channel; a high-pressure fuel cavity and a high-pressure flame-retardant gas cavity are arranged in the precursor compression surface; the step part is provided with a fuel injection port and a flame-retardant gas injection port; the fuel injection port is communicated with the high-pressure fuel cavity, and the flame-retardant gas injection port is communicated with the high-pressure flame-retardant gas cavity.

Further, the fuel injection port is located above the flame retardant gas injection port.

Furthermore, the front body compression surface comprises a first-stage compression wedge surface and a second-stage compression surface which are sequentially extended backwards, and the front end of the second-stage compression surface and the first-stage compression surface form a turning point; the rear end of the second-stage compression surface is connected with the inner wall surface of the air inlet channel, and the step part is positioned on the second-stage compression surface; the second-stage compression surface is stepped to form a front section and a rear section which are not collinear but parallel; the back step surface is vertical to the second stage compression surface of the front section and the second stage compression surface of the back section.

Further, the distance between the back step surface and the inflection point of the compression surface is at least 100 mm.

Furthermore, the inflection point of the back step surface from the compression surface is 300 mm.

Further, the injection flow rate of the flame-retardant gas is 1.177 kg/s.

Further, the fuel is hydrogen; the high pressure flame retardant gas is nitrogen.

Further, the fuel injection port and the flame-retardant gas injection port are both slits; the surface normal directions of the fuel injection port and the flame-retardant gas injection port are both parallel to the surface normal direction of the back step surface.

Furthermore, the inner wall surface is a surface of the air inlet channel arranged close to the outer surface of the aircraft body.

Furthermore, an end distance is arranged between the step surface and the inlet of the channel in the air inlet channel.

The technical scheme of the invention has the following beneficial effects:

according to the invention, the back step surface is arranged on the compression surface of the precursor of the hypersonic ram air inlet for pre-injection of fuel, and the precursor with a longer hypersonic binary air inlet is used for realizing the advanced mixing of the fuel and the incoming air, so that the stable performance of the super-combustion or detonation combustion is ensured. Besides the pre-injection of fuel, the rear end face of the step is provided with a flame-retardant gas injection port parallel to the normal direction of the surface below the fuel injection port. The injection of the flame retardant gas isolates the contact of fuel and the inner wall surface of the air inlet, so that the combustible mixture is prevented from being ignited in advance in the air inlet, and the injection of the flame retardant gas can improve the distribution of the fuel on each section of the downstream of the air inlet.

Drawings

FIG. 1(a) is a schematic structural diagram of a fixed geometry binary hypersonic inlet with a rear step slot pre-injection according to the present invention;

FIG. 1(b) is a schematic structural diagram of the vicinity of the back step surface of the fixed geometry binary hypersonic inlet with back step slit pre-injection according to the present invention;

FIG. 2(a) is a numerical shading graph of a fixed geometry binary hypersonic inlet port without a background step end face in a first validation experiment;

FIG. 2(b) is a numerical shading graph of a fixed-geometry binary hypersonic inlet channel when the distance between the end surface of the back step and the inflection point of the compression surface is 100mm in a first verification experiment;

FIG. 2(c) is a numerical shading graph of a fixed-geometry binary hypersonic inlet channel when the distance between the end surface of the back step and the inflection point of the compression surface is 200mm in a first verification experiment;

FIG. 2(d) is a numerical shading graph of a fixed-geometry binary hypersonic inlet channel when the distance between the end surface of the back step and the inflection point of the compression surface is 300mm in a first verification experiment;

FIG. 2(e) is a numerical shading graph of a fixed-geometry binary hypersonic inlet channel when the distance between the end surface of the back step and the inflection point of the compression surface is 400mm in a first verification experiment;

FIG. 3(a) is a numerical shading graph of a fixed-geometry binary hypersonic inlet channel when the distance between the end surface of the back step and the inflection point of the compression surface is 100mm in a second verification experiment;

FIG. 3(b) is a numerical shading graph of a fixed-geometry binary hypersonic inlet channel when the distance between the back step end surface and the inflection point of the compression surface is 200mm in a second verification experiment;

FIG. 3(c) is a numerical shading graph of a fixed-geometry binary hypersonic inlet channel when the distance between the end surface of the back step and the inflection point of the compression surface is 300mm in a second verification experiment;

FIG. 3(d) is a numerical shading graph of a fixed geometry binary hypersonic inlet channel when the back step end surface is 400mm away from the compression surface inflection point in the second verification experiment;

FIG. 4 is a graph showing the trend of the flow coefficient of the inlet channel moving backward along the end face of the subsequent step in the second verification experiment

FIG. 5 shows the distribution of the equivalence ratio of oil and gas at the outlet cross section of the inlet duct corresponding to different positions of the background step in the second verification experiment

FIG. 6(a) is a numerical shading chart of the inlet at a nitrogen pre-injection flow of 0.637kg/s in the third verification experiment

FIG. 6(b) is a numerical shading graph of an intake port at a nitrogen pre-injection flow of 0.913kg/s in the third verification experiment

FIG. 6(c) is a numerical shading graph of the inlet at a nitrogen pre-injection flow of 1.074kg/s in the third verification experiment

FIG. 6(d) is a numerical shading graph of the inlet at a nitrogen pre-injection flow of 1.177kg/s in the third verification experiment

FIG. 7 is a graph showing the trend of the flow coefficient of the inlet in the third verification experiment with the increase of the nitrogen pre-injection flow

FIG. 8 is an oil-gas equivalence ratio distribution of an outlet section of an air inlet passage at different nitrogen pre-injection flow rates in the third verification experiment.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

As shown in fig. 1, a fixed geometry binary hypersonic inlet channel with a pre-injection in a precursor comprises a lip cover 1, an inner wall surface 2, a compression surface 3 extending forwards from the inner wall surface, a back step end surface 4 arranged on the compression surface 3, a high-pressure gas cavity 9 and a high-pressure flame-retardant gas cavity 10, wherein the high-pressure gas cavity 9 and the high-pressure flame-retardant gas cavity 10 are arranged in the compression surface 3; the lip shroud 1, inner wall surface 2 forms an inner channel 5 and an equal straight section 6 extending rearwardly from the inner channel. If the air inlet is used in an aircraft, the inner wall surface 2 is the surface of the air inlet that is disposed adjacent to the outer surface of the fuselage of the aircraft.

In order to realize the sufficient mixing of fuel and incoming air by utilizing the longer flow direction length of the air inlet channel, a back step surface 4 which is smaller than the whole size of the air inlet channel is arranged on the second-stage compression surface of the air inlet channel and is used for the arrangement of an injection port. This simpler back-end configuration has less effect on the overall precursor wave system of the inlet. The rear step surface boundary is connected to the compression surface 3 via an upper edge 41 and a lower corner 42. Due to the existence of the back step surface 4, the compression surface 3 can be divided into three parts, the first part is a rear section of the second-stage compression surface extending from the inner wall surface to the lower corner 42 of the back step surface, the second part is a front section of the second-stage compression surface between the upper edge 41 of the back step surface and the turning point 31, and the third part is a first-stage compression surface before the turning point 31. The second stage compression surface is divided into a front stage and a rear stage which are not collinear but parallel, but the two stages have the same effect of changing the airflow direction, so the second stage compression surface is still called the second stage compression surface. And the step surface 4 is vertical to the two sections of second-stage compression surfaces.

Further explaining the design mode of the two-stage compression surface of the air inlet channel, the front sections of the first-stage compression surface and the second-stage compression surface are designed according to the intersection of the induced oblique shock waves on the front edge of the lip cover 1 of the air inlet channel. The distance between the upper edge 41 of the back step surface and the turning point 31 is properly designed according to actual conditions, so that the back step surface does not influence the compression wave system of the front body of the air inlet channel, the capture effect of the air inlet channel on the incoming air is ensured, and the pre-injected fuel is mixed with the main flow in the air inlet channel. Then, a wall surface parallel to the front stage of the second-stage compression surface is formed from the rear step surface lower corner 42 to the inner wall surface 5 as the rear stage of the second-stage compression surface.

Two upper slits 7 and two lower slits 8 for supersonic jetting are arranged on the end surface of the back step, the upper slits 7 and the lower slits 8 are arranged in parallel, the normal directions of the two are both parallel to the normal direction of the surface of the back step surface 4, namely, the air flow is jetted out perpendicular to the back step surface. A high-pressure hydrogen chamber 9 and a high-pressure nitrogen chamber 10 are provided in the compression face 3 as a source of hydrogen and nitrogen gas required for injection. The upper slit 7 is a fuel injection port, the slit injection port is connected with a high-pressure hydrogen chamber 9 arranged in the compression surface 3 through a pipeline, and the slit area is determined by the flow, Mach number, total pressure and total temperature of the fuel injection. If the fuel is injected from the upper slit alone, the fuel discharge port expands toward the compression surface 3 and then diffuses toward the main flow in the vicinity of the wall surface, which may cause uneven distribution of the fuel in the main flow and ignition of the high-temperature boundary layer of the compression surface 3. Therefore, the lower slits 8 are arranged for injecting the flame-retardant gas, so that the distribution of the fuel in the main flow is adjusted, and the contact between the fuel and a high-temperature boundary layer is blocked. The lower slit 8 is connected with the high-pressure nitrogen cavity through a pipeline, and the area is determined by the flow, Mach number, total pressure and total temperature of flame-retardant gas injection.

Next, in order to verify the present invention, the following verification experiment was designed. In the experiment, the binary hypersonic inlet channel adopts a binary three-wave system hypersonic inlet channel with the designed incoming flow Mach number of Ma 10. The front body compression surface 3 of the air inlet channel is provided with two stages of compression wedge surfaces which extend backwards in sequence, compression angles corresponding to the two stages of compression wedge surfaces are all 6.6 degrees, and at the moment, a front edge shock wave of the first stage of compression surface and a second stage shock wave emitted by a turning point 31 just converge at a lip. And a back step end face is arranged on the second-stage compression face, and the height of the back step end face, namely the distance from the upper edge 41 to the lower corner 42, is 10.4 mm.

And a first verification experiment is carried out, namely the influence of the design of the end face of the rear step on the flow field of the air inlet channel is verified, and the influence of the position of the end face of the rear step on the flow field of the air inlet channel is verified. To achieve this result, the position of the back step along the flow direction, i.e. the distance between the upper edge 41 of the back step end surface and the inflection point 31 of the compression surface, is varied. And comparing the distances L between the air inlet channel without the rear step structure and the front edge of the second-stage compression surface, namely the outlet Mach number, the flow coefficient and the total pressure recovery coefficient of the air inlet channel with the distances L being 100mm, 200mm, 300mm and 400mm, and evaluating the configuration of the rear step surface and the influence of the rear step end surface on the performance of the air inlet channel when the rear step end surface is arranged at different positions of the second-stage compression surface. Fig. 2(a) to fig. 2(e) are global numerical shading graphs of the five air inlets, and it can be seen from the graphs that after the rear step end surface is arranged on the second-stage compression surface of the air inlet, the precursor wave system structure of the air inlet has no obvious change, and the precursor shock waves still intersect at the lip, which shows that the flow capturing capability of the air inlet is not significantly affected by the arrangement of the rear step, and the air inlet provided with the rear step end surface can still provide sufficient air for the combustion chamber. And along with the back step terminal surface along the second compression face to the in-channel in the intake duct in-process of approaching, the interior channel wave system structure of intake duct has slight change, leads to the intake duct that back step terminal surface position is different to have the difference on the performance. The performance parameters of the air inlet channels which are obtained through calculation when fuel pre-injection is not carried out are shown in the following table, and it can be seen from the table that the Mach number and the total pressure recovery coefficient of the outlet of the air inlet channel are influenced by arranging the back step end surface on the second-stage compression surface of the air inlet channel. The closer the rear step end face is to the front edge of the second-stage compression surface, the higher the total pressure recovery of the outlet of the air inlet channel is, and the higher the Mach number of the outlet is. When the distance between the back step surface and the inflection point 31 of the compression surface is 100mm, the Mach number of the outlet of the air inlet channel is improved by 0.2 compared with the design of the end surface without the back step, the sufficient compression of the incoming flow can be still ensured by the air inlet channel, and the low mechanical energy loss of the air captured by the air inlet channel and the strong work-doing capability are also ensured by the high total pressure recovery coefficient. In summary, the air inlet channel provided with the back step end face still has the advantages of capturing sufficient incoming air, having sufficient compression capacity for the captured air and having feasibility.

Position of background step along flow direction	Outlet flow rate	Coefficient of flow	Mach number of outlet	Total pressure recovery coefficient
					End face without rear step	6.40kg/s	1.0	3.9	0.156
100mm	6.39kg/s	0.99	4.1	0.190
					200mm	6.39kg/s	0.99	4.1	0.191
300mm	6.39kg/s	0.99	4.1	0.170
					400mm	6.40kg/s	1.0	4.0	0.150

According to the results obtained in the first experiment, the trapped flow of the air inlet channel is about 6.39kg/s no matter whether the position of the back step surface is changed, and the required hydrogen flow of the air inlet channel is about 0.185kg/s calculated according to the global equivalence ratio of 1. Therefore, a second experiment was conducted for four types of inlet ports having a distance L of 100mm, 200mm, 300mm and 400mm between the rear step end surface and the compression surface inflection point 31, in which 0.185kg/s of hydrogen was injected into the rear step end surface of each type of inlet port through the slit 7, and 0.637kg/s of nitrogen, which is a flame retardant gas, was injected into the lower slit 8. The influence of the jet position on the air inlet performance and the pre-injected fuel mixing is verified.

Fig. 3(a) to 3(d) show the numerical shading graphs of the four air inlets after fuel pre-injection, and it can be seen from the graphs that when the back step surface is close to the inflection point 31 of the compression surface, the shock wave generated by injection induction intersects with the shock wave generated by the second-stage compression surface, and the shock wave generated by convergence has a larger angle, so that the shock wave of the front body of the air inlet is converged in front of the lip. However, in this experiment, when the inflection point of the back step surface is 300mm from the compression surface, that is, as shown in fig. 3(c), the precursor shock wave converges at the lip, and the inlet channel has no overflow phenomenon. And the distance between the back step end surface and the inflection point of the compression surface is further increased, so that the shock wave induced by the fuel pre-injection can be injected into the channel in the air inlet channel, and the precursor wave system of the air inlet channel is not influenced any more. Fig. 4 shows a variation trend of the flow coefficient of the air intake duct along with an increase in the distance between the inflection point of the end surface of the back step and the compression surface, and it can be seen from the graph that the flow coefficient significantly increases when the end surface of the back step is close to the inner passage of the air intake duct. The background stage pre-injection structure can realize the injection of the fuel required by the engine on the basis of ensuring the capture capacity of the air inlet to the incoming flow air without influencing the precursor wave system of the air inlet.

FIG. 4 shows the distribution of the oil-gas equivalence ratio of the outlet section of the air inlet passage when the rear step pre-injection structure is at different positions. As can be seen from the figure, the lower half of the outlet section of the air inlet channel is generally higher in air-fuel equivalence ratio, but the upper half of the outlet section is not zero, which indicates that the fuel has diffused to the upper half of the outlet of the air inlet channel. When the inflection point of the back step surface from the compression surface is 100mm, the oil-gas equivalence ratio at the upper wall surface of the air inlet channel is close to 1, and the requirement of combustion in the combustion chamber is met. In addition, along with the in-process that the backstage end is close to the passageway in the intake duct, the oil gas distribution of intake duct export the latter half also changes to the required appropriate equivalence ratio of chemical reaction gradually, and when backstage apart from compression surface inflection point was 300mm, intake duct exit cross section the latter half oil gas distribution became the best, and the backstage can lead to intake duct exit cross section oil gas distribution to inhomogeneous development if continue to move backward along the flow direction.

In summary, it can be seen that when the position of the back stage injection structure is close to the inner channel of the intake port, the capability of the intake port to capture the incoming air is improved, but the fuel distribution at the upper half of the outlet cross section of the intake port is developed towards lean oil, and the fuel distribution at the lower half of the outlet cross section of the intake port tends to be uniform and then develops into a rich state. Therefore, the capacity of the air inlet channel for capturing the incoming air and the condition of mixing of the fuel in the air inlet channel need to be comprehensively considered in the design process, and the optimal position of the background step structure needs to be selected. In the experiment, the corner distance between the rear step and the compression surface is 300mm, and a third experiment is performed on the basis of the configuration, so that the influence of different nitrogen injection flow of the flame-retardant gas on the performance of the air inlet and the fuel mixing is verified.

The injection of the flame-retardant gas nitrogen also has certain influence on the wave system structure of the air inlet and the distribution of fuel at the outlet section of the air inlet, so that the third experiment is carried out, and the influence of different nitrogen injection flows is analyzed by comparing four conditions of 0.637kg/s, 0.913kg/s, 1.074kg/s and 1.177kg/s of the nitrogen injection flow.

Fig. 6(a) to (d) are numerical shading graphs of nitrogen injection at different flow rates, and it can be seen from the graphs that as the nitrogen flow rate increases, the shock wave angle generated by injection induction increases, and the shock wave angle intersects with the second-stage shock wave in advance, so that the wave system of the front air inlet is lifted and converged in front of the lip, and the capture capacity of the air inlet on the incoming air is reduced. As can be seen further in conjunction with FIG. 7, the port flow coefficient decreases overall as the nitrogen injection flow increases. However, in this experiment, when the nitrogen injection flow rate was increased to 1.177kg/s, it was still possible to ensure that more than 85% of the incoming flow was captured by the inlet.

In addition, although the flow coefficient of the inlet passage decreases, as shown in fig. 8, the distribution of the air-fuel equivalence ratio at the outlet section of the inlet passage tends to be uniform as the flow of the injected nitrogen gas increases. The oil-gas equivalent ratio of the rich oil area at the lower half part of the outlet section of the air inlet channel observed in the original experiment II is gradually reduced, and the oil-gas equivalent ratio of the lean oil area at the upper half part is gradually increased. The oil-gas equivalence ratio of the upper half area and the lower half area of the outlet section of the air inlet channel is close to the proper oil-gas ratio 1 along with the increase of the nitrogen injection flow. Therefore, the third experiment can be summarized, the inlet flow coefficient is reduced along with the increase of the nitrogen injection flow, but the hydrogen can be better mixed with the incoming air. Therefore, the proper injection flow of the flame-retardant gas nitrogen is selected, so that the sufficient mixing of the hydrogen can be realized while the outlet flow of the air inlet passage is ensured, and the proper combustible mixture is provided for the combustion of the engine.

Three experiments are integrated, so that the background step position in the invention is reasonably designed, and the optimal flame-retardant gas injection flow is selected, so that a binary hypersonic inlet channel which gives consideration to both the performance of the inlet channel and the pre-mixing of fuel can be realized. The invention can fully utilize the longer inner and outer flow passages of the hypersonic air inlet channel to realize the mixing of the incoming air and the fuel by using a simpler geometric structure, and provides proper gas mixed incoming flow for the combustion of the hypersonic air suction type engine.

Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that changes may be made in the embodiments and/or equivalents thereof without departing from the spirit and scope of the invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.