A powered reverse-flow combustion chamber for a powder scramjet

Abstract

This invention relates to an active recirculation combustion chamber for a powder scramjet engine, comprising: a main flow channel structure and a cavity structure mounted on the main flow channel structure; the cavity structure includes: a cavity front edge, a cavity rear edge, a cavity bottom wall, and a cavity side wall; a fuel supply structure is provided at the cavity rear edge, connecting the front and rear sides of the cavity rear edge and used for supplying powdered fuel; the extension direction of the hollow channel of the fuel supply structure is parallel to the cavity bottom wall; the lower wall surface of the hollow channel is flush with the inner surface of the cavity bottom wall; the opening of the hollow channel facing the cavity front edge is a regular opening with a length greater than its width, and the length direction of the opening of the channel front edge is parallel to the cavity bottom wall. This invention, by improving the powdered fuel supply method and cooperating with a typical cavity combustion chamber, avoids the adverse effects of supersonic flow on the combustion process, achieving efficient combustion of powdered fuel in a scramjet engine.

Description

Technical Field

[0001] This invention relates to the field of scramjet engines, and more particularly to an active recirculation combustion chamber for a powder scramjet engine. Background Technology

[0002] With the development of aircraft propulsion technology, especially driven by the strategic needs of hypersonic cruise weapons, high-performance propulsion solutions have attracted much attention. New concept engines using high-energy powder fuel offer numerous advantages, such as easily adjustable flow rate, high specific impulse, and minimal dissociation of high-temperature combustion products. However, research has revealed that powder fuels possess properties different from traditional liquid or solid fuels. Boron, in particular, with its theoretically superior performance, exhibits combustion processes that are largely typical surface heterogeneous reactions. The fuel and oxidizer are mixed at the particle level rather than at the molecular level. In a supersonic flow, the powder reaches a high velocity after being accelerated by the mainstream. The gas recirculation zone formed by a traditional concave chamber cannot effectively disturb the particle motion, thus reducing the flame stabilization and combustion enhancement effect of the concave chamber. Summary of the Invention

[0003] The purpose of this invention is to provide an active recirculation combustion chamber for a powder scramjet engine.

[0004] To achieve the above-mentioned objectives, the present invention provides an active recirculation combustion chamber for a powder scramjet engine, comprising: a main channel structure and a concave cavity structure connected to the main channel structure;

[0005] The cavity structure includes: a front edge of the cavity, a rear edge of the cavity, a bottom wall of the cavity, and a side wall of the cavity;

[0006] The rear edge of the cavity is provided with a fuel supply structure that connects the front and rear sides of the rear edge of the cavity and is used for supplying powdered fuel.

[0007] The extension direction of the hollow channel in the fuel supply structure is parallel to the bottom wall of the cavity;

[0008] The lower wall of the hollow channel is flush with the inner side of the bottom wall of the concave cavity;

[0009] The hollow channel has a regular opening at its front end facing the front edge of the cavity, with a length greater than its width, and the length direction of the channel front opening is parallel to the bottom wall of the cavity.

[0010] According to one aspect of the invention, the hollow channel has a channel portion with a constant cross-section;

[0011] The equal-section channel portion starts from the opening at the front end of the channel and extends in a direction away from the opening at the front end of the channel.

[0012] According to one aspect of the invention, the extension length of the equal-section channel portion is greater than the length of the opening at the front end of the channel.

[0013] According to one aspect of the invention, the fuel supply structure is arranged such that the front end of the front edge of the cavity is flush with the inner wall of the rear edge of the cavity.

[0014] According to one aspect of the invention, the fuel supply structure extends into the hollow cavity of the cavity structure toward the front end of the cavity leading edge.

[0015] According to one aspect of the invention, a turbulence structure is provided at the leading edge of the cavity;

[0016] The turbulence structure is plate-shaped and is arranged perpendicular to the front edge of the cavity;

[0017] The upper edge of the turbulence structure is flush with the inner wall of the main channel structure, or the upper edge of the turbulence structure is lower than the inner wall of the main channel structure.

[0018] According to one aspect of the invention, a plurality of the turbulence structures are arranged at intervals on the leading edge of the cavity;

[0019] The arrangement direction of the plurality of the disturbance structures is consistent with the length direction of the opening at the front end of the hollow channel.

[0020] According to one aspect of the invention, the angle between the leading edge of the cavity and the inner lower wall surface ranges from 30° to 60° along the incoming flow direction.

[0021] According to one aspect of the invention, it further includes: an ignition device;

[0022] The ignition device is embedded in the bottom wall of the cavity;

[0023] The ignition device is located between the front edge of the cavity and the front end of the fuel supply structure.

[0024] According to one aspect of the invention, it further includes: a protective structure;

[0025] The protective structure is fixed to the bottom wall of the cavity and is adjacent to the ignition device;

[0026] The protective structure is located on the side opposite to the front end of the ignition device and the fuel supply structure;

[0027] The fuel supply structure is integrally formed with the cavity structure.

[0028] According to one aspect of the present invention, the concave cavity structure, which serves as the main body of the present invention, has the advantages of simple structure and low internal resistance. In addition, the structure of the present invention has a larger size than that of a general concave cavity combustion chamber, including the cavity length and cavity depth.

[0029] According to one aspect of the present invention, by improving the powder fuel supply method and cooperating with a typical concave combustion chamber, the present invention achieves efficient combustion of powder fuel in a scramjet engine.

[0030] According to one aspect of the present invention, a powder supply channel is arranged at the bottom of the rear edge of the cavity. During operation, the powdered fuel enters the cavity through the supply channel and merges with the backflow formed at the rear edge of the cavity to achieve the flow of air and the efficiency of mixing and combustion in the combustion chamber.

[0031] According to one aspect of the present invention, an ignition device is arranged on the bottom wall of the cavity near the leading edge of the cavity for rapid and reliable repeated ignition.

[0032] According to one aspect of the present invention, the present invention, through the concave cavity leading edge and the corresponding turbulence structure, can more easily ensure that the powdered fuel smoothly enters the mainstream for further combustion, thereby achieving the advantage of improving combustion efficiency, which is more beneficial to further ensuring the working performance of the present invention.

[0033] According to one aspect of the present invention, the present invention effectively achieves rapid and reliable ignition and stable and efficient combustion in a powder scramjet engine. The fuel supply structure and its hollow channel create different recirculation zones within the concave cavity structure. In particular, the passive recirculation zone exhibits a high-temperature, low-velocity effect, further increasing the temperature of the powdered fuel at the bottom of the concave cavity corresponding to the fuel supply structure and reducing its velocity. This helps shorten the ignition delay time, enabling the powder scramjet engine to achieve rapid and reliable ignition under the action of the ignition device. Furthermore, the powdered fuel is supplied from the bottom of the rear edge of the concave cavity to actively participate in the recirculation, enhancing the influence of the concave cavity structure on the powdered fuel and extending its residence time in the scramjet engine. In addition, the active recirculation zone, passive recirculation zone, and shear zone within the concave cavity work together to stabilize the flame, contributing to flame stability and improved combustion efficiency.

[0034] According to one aspect of the present invention, addressing the issue of low combustion efficiency due to short residence time of fuel in the combustion chamber caused by the movement of fuel with the mainstream in supersonic flow, the active recirculation combustion chamber of the present invention creatively guides the combustion zone towards the recirculation zone, overcoming to some extent the disadvantages of high flow velocity in supersonic combustion chambers. Simultaneously, due to the reduced flow velocity, the temperature inside the concave cavity is generally higher than that of the mainstream; combustion organization within the recirculation cavity utilizes the advantage of the high total temperature of the incoming flow, greatly improving combustion efficiency.

[0035] According to one aspect of the present invention, the technical concept of actively guiding the combustion zone to the recirculation zone in the active recirculation combustion chamber can be further extended to other supersonic propulsion devices, which is more beneficial for achieving high combustion efficiency in other supersonic propulsion devices. Attached Figure Description

[0036] Figure 1 This is a schematic three-dimensional structural diagram of the active recirculation combustion chamber of a powder scramjet engine according to an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram illustrating the internal flow region division of the concave cavity structure in the active recirculation combustion chamber of a powder scramjet engine according to an embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram illustrating the internal flow state of the concave cavity structure in the active recirculation combustion chamber of a powder scramjet engine according to an embodiment of the present invention.

[0039] Figure 4 This is a schematic diagram illustrating the internal flow state of the concave cavity structure in the active recirculation combustion chamber of a powder scramjet engine according to another embodiment of the present invention.

[0040] Figure 5 This is a schematic diagram illustrating the internal flow state of the concave cavity structure in the active recirculation combustion chamber of a powder scramjet engine according to another embodiment of the present invention.

[0041] Figure 6 This is a schematic diagram illustrating the arrangement of the flow-around structure in the active recirculation combustion chamber of a powder scramjet engine according to another embodiment of the present invention. Detailed Implementation

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative effort.

[0043] In describing embodiments of the present invention, the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" express orientations or positional relationships based on the orientations or positional relationships shown in the relevant drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on the present invention.

[0044] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The embodiments cannot be described in detail here, but the embodiments of the present invention are not limited to the following embodiments.

[0045] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, an active recirculation combustion chamber for a powder scramjet engine includes: a main flow channel structure 1 and a cavity structure 2 mounted on the main flow channel structure 1; wherein the cavity structure 2 and the main flow channel structure 1 can be integral or detachably connected. In this embodiment, the main flow channel structure 1 is a hollow rectangular cylinder with a constant cross-section. In this embodiment, the cavity structure 2 includes: a cavity leading edge 21, a cavity trailing edge 22, a cavity bottom wall 23, and a cavity side wall 24; wherein the cavity leading edge 21, the cavity trailing edge 22, the cavity bottom wall 23, and the cavity side wall 24 are all plate-like structures, wherein the cavity leading edge 21 and the cavity trailing edge 22 are located on the same side of the cavity bottom wall 23 and are respectively connected to the opposite ends of the cavity bottom wall 23. In this embodiment, the front edge 21 and the rear edge 22 of the cavity are respectively inclined relative to the bottom wall 23 of the cavity, wherein the front edge 21 and the rear edge 22 of the cavity extend inclinedly away from each other in a direction away from the bottom wall 23. In this embodiment, two opposite sidewalls 24 of the cavity are provided and are respectively connected to the edges of the front edge 21, the rear edge 22 of the cavity, and the bottom wall 23 of the cavity, thereby forming a complete cavity structure 2, and the interior of the cavity structure 2 forms a trapezoidal active reflux cavity.

[0046] In this embodiment, the rear edge 22 of the cavity is provided with a fuel supply structure 22a that connects the front and rear sides of the rear edge 22 of the cavity and is used for supplying powdered fuel; wherein, the fuel supply structure 22a has a hollow channel 22a1, and the hollow channel 22a1 forms an input connection interface for connecting the powdered fuel input pipeline at the rear end of the fuel supply structure 22a, and the hollow channel 22a1 forms a channel front opening at the front end of the fuel supply structure 22a for conveying powdered fuel into the cavity structure 2.

[0047] In this embodiment, the extension direction of the hollow channel 22a1 of the fuel supply structure 22a is parallel to the bottom wall 23 of the cavity.

[0048] In this embodiment, the lower wall surface of the hollow channel 22a1 is flush with the inner surface of the cavity bottom wall 23. The hollow channel 22a1 has a constant cross-section channel portion 22a11, which, through its rectifying effect, adjusts the direction of fuel velocity at the channel's front opening. In this embodiment, the constant cross-section channel portion 22a11 extends from the channel's front opening in a direction away from it. In this embodiment, the remaining channel portions in the hollow channel 22a1 connected to the constant cross-section channel portion 22a11 are configured according to actual needs; they can be either constant or unequal cross-section channel portions, which will not be elaborated further here.

[0049] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the fuel supply structure 22a extends into the hollow cavity (i.e., the active recirculation cavity) of the cavity structure 2 towards the front end of the cavity leading edge 21. In this embodiment, the left and right walls of the hollow channel 22a1 are flush with the inner surfaces of the cavity sidewall 24, thereby ensuring that the positions where the fuel supply structure 22a connects to the cavity bottom wall 23 and the cavity sidewall 24 are flush, effectively avoiding the obstruction of powder fuel delivery by a stepped structure. Furthermore, by extending the fuel supply structure 22a into the active recirculation cavity, the upper surface of the fuel supply structure 22a can replace part of the cavity bottom wall 23, so that the active recirculation cavity portion near the cavity trailing edge 22 forms a passive recirculation zone A, thereby generating a trailing edge recirculation a flowing along the cavity trailing edge 22 and the upper surface of the fuel supply structure 22a in the passive recirculation zone A.

[0050] Furthermore, since the active recirculation chamber between the fuel supply structure 22a and the leading edge 21 of the concave cavity still has the bottom wall 23 of the concave cavity as its bottom structure, an active recirculation zone B is formed in the active recirculation chamber between the fuel supply structure 22a and the leading edge 21 of the concave cavity. In the active recirculation zone B, the trailing edge recirculation a in the passive recirculation zone A detaches from the upper side of the fuel supply structure 22a and flows to the bottom wall 23 of the concave cavity to form a bottom recirculation b. The input powdered fuel (including fluidizing gas) is used as the input recirculation e to achieve the mixing of the input recirculation e and the bottom recirculation b to generate the leading edge recirculation c, which can then flow along the leading edge 21 of the concave cavity into the mainstream region C above the active recirculation chamber.

[0051] In this embodiment, since the main channel structure 1 needs to input external air, a main channel region C for the flow of the main air d is formed above the cavity structure 2, and a shear region D for the flow of shear air f is formed at the junction of the main channel structure 1 and the cavity structure 2. The passive recirculation region A and the active recirculation region B are located below the shear region D.

[0052] By setting the fuel supply structure 22a at the bottom wall 23 of the cavity and connecting it to the rear edge 22 of the cavity, a portion of the bottom wall 23 of the cavity is replaced by the upper side of the fuel supply structure 22a. This achieves the function of dividing the circulation area inside the cavity while facilitating the input of external powdered fuel.

[0053] Furthermore, by placing the hollow channel 22a1 for supplying powdered fuel at the bottom rear edge of the active recirculation chamber and parallel to the bottom wall 23 of the concave chamber, the powdered fuel can be directly and fully mixed with the recirculation passing through the passive recirculation zone A at the same time as it is input. Under the action of the input powdered fuel, the entire mixed airflow can be effectively driven to be incorporated into the mainstream airflow d along the front edge 21 of the concave chamber in the active recirculation zone B, so that the powdered fuel can be further burned in the mainstream region C and the shear region D.

[0054] Furthermore, during the further combustion of powdered fuel in the mainstream region C and shear region D, as the airflow flows, the powdered fuel and combustion products in the shear region D can further enter the passive recirculation region A to achieve further combustion or provide a high-temperature region for the entire active recirculation chamber.

[0055] In this embodiment, the rear end face of the fuel supply structure 22a is flush with the outer surface of the rear edge 22 of the cavity.

[0056] With the above configuration, the fuel supply structure 22a extends into the hollow cavity to the longest length. At this time, the area of ​​the passive recirculation zone A formed is the largest, making the mixing of powdered fuel and recirculation more thorough and effective.

[0057] like Figure 4 As shown, according to another embodiment of the present invention, the fuel supply structure 22a extends into the hollow cavity (i.e., active return cavity) of the cavity structure 2 with the front end of the cavity leading edge 21, while the rear end of the fuel supply structure 22a extends beyond the outer surface of the cavity trailing edge 22.

[0058] With the above configuration, a portion of the fuel supply structure 22a can extend into the hollow cavity, while a portion of the fuel supply structure 22a is located outside the cavity structure 2. The size of the passive recirculation zone A can be controlled by the length of the fuel supply structure 22a extending into it. This effectively reduces the occupancy of the cavity structure 2 while ensuring the mixing effect of the powdered fuel and the recirculation, thereby reducing the overall size of the cavity structure 2. As a result, the cavity structure 2 of the present invention can achieve good combustion effect while miniaturizing its structural size.

[0059] like Figure 5 As shown, according to another embodiment of the present invention, the front end of the fuel supply structure 22a facing the front edge 21 of the cavity is flush with the inner side of the rear edge 22 of the cavity, while the rear end of the fuel supply structure 22a is disposed on the outer side of the cavity structure 2.

[0060] With the above configuration, the fuel supply structure 22a does not extend into the hollow cavity, so that the fuel supply structure 22a is outside the cavity structure 2. This configuration minimizes the area of ​​the passive recirculation zone A, but completely avoids occupying the internal space of the cavity structure 2, thereby making the overall size of the cavity structure 2 smaller and more suitable for situations where the size of the cavity structure 2 is limited, thus making the scope of application of the present invention wider.

[0061] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the opening at the front end of the hollow channel 22a1 facing the front edge 21 of the cavity is a regular opening with a length greater than its width, and the length direction of the opening at the front end of the channel is parallel to the bottom wall 23 of the cavity. In this embodiment, the opening at the front end of the channel is rectangular. In this embodiment, the length of the opening at the front end of the channel is limited by the width dimension of the cavity structure 2, and its width is determined by the opening area and length of the opening at the front end of the channel. The opening area of ​​the opening at the front end of the channel is limited by the airflow state at its location during the design process. Generally, the throat upstream of the fuel supply structure 22a controls the flow rate of fuel and fluidizing gas, and the opening area of ​​the opening at the front end of the channel adjusts the outlet static pressure and flow velocity. Thus, the opening width of the opening at the front end of the channel is selected when the outlet static pressure is higher than the bottom static pressure of the cavity structure 2 and the outlet velocity is as small as possible.

[0062] With the above settings, the supply direction of the powdered fuel can be parallel to the flow direction of the mainstream air d in the mainstream region C, while the powdered fuel can be better distributed evenly along the bottom wall 23 of the concave cavity, so that the powdered fuel can be better mixed evenly with the airflow passing through the passive recirculation region A.

[0063] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the extension length of the equal cross-section channel portion 22a11 is greater than the length of the opening at the front end of the channel, so as to achieve the rectification effect on fuel and fluidizing gas, so as to conveniently adjust the initial velocity direction of fuel and fluidizing gas entering the concave cavity structure 2 to be parallel to the bottom of the concave cavity structure 2.

[0064] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, a flow-disrupting structure 211 is provided on the leading edge 21 of the concave cavity. In this embodiment, the flow-disrupting structure 211 is plate-shaped and is arranged perpendicular to the leading edge 21 of the concave cavity. In this embodiment, the flow-disrupting structure 211 can be configured as a right-angled triangular plate, with its hypotenuse (i.e., base) fixedly connected to the leading edge 21 of the concave cavity, one of its straight sides (sides) being flush with or lower than the inner lower wall surface of the main flow channel structure 1, and the other straight side (side) being perpendicular to the bottom wall 23 of the concave cavity. (See also...) Figure 6 In another embodiment, the turbulence structure 211 can be configured as an obtuse triangular plate with its base fixedly connected to the front edge 21 of the cavity. One end of one side is connected to the inner lower wall of the main channel structure 1, so that an inclined surface lower than the inner lower wall is formed in the length direction of the side. The other side is also set perpendicular to the bottom wall 23 of the cavity.

[0065] With the above settings, by setting the turbulence structure 211 at the front edge 21 of the cavity, it is possible to effectively ensure that the powdered fuel is smoothly cut into the mainstream air d for combustion and enhance the mixing effect of the powdered fuel and the mainstream air d.

[0066] like Figure 1 As shown, according to one embodiment of the present invention, the angle between the leading edge 21 of the cavity and the inner lower wall surface of the cavity along the incoming flow direction ranges from 30° to 60°. In this embodiment, the angle between the leading edge 21 of the cavity and the inner lower wall surface of the cavity can be set to 45°. Of course, its tilt angle can also be set to other values, which can be selected according to actual design requirements. By setting the tilt angle of the leading edge 21 of the cavity within the above range, it is more beneficial to facilitate the smooth entry of the backflow into the mainstream, avoid affecting the mainstream, and optimize the backflow entry effect.

[0067] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, a plurality of turbulence structures 211 are arranged at intervals on the front edge 21 of the cavity; wherein the arrangement direction of the plurality of turbulence structures 211 is consistent with the length direction of the opening at the front end of the hollow channel 22a1.

[0068] In this embodiment, the spacing between adjacent turbulence-disrupting structures 211 is 1.5 to 2 times the thickness of the turbulence-disrupting structure 211. The thickness of the turbulence-disrupting structure 211 can be set to 5 to 10 mm.

[0069] With the above configuration, multiple turbulence structures 211 arranged at intervals can form a bottom-inclined guide channel between adjacent turbulence structures 211 and the front edge 21 of the cavity, which can more easily guide the return flow into the mainstream input of the mainstream channel structure 1. Each turbulence structure 211 has a vertical side, which is perpendicular to the direction of the return flow, so that it can obstruct and disturb part of the return flow, allowing it to enter the active return flow zone B for flow circulation.

[0070] Furthermore, by setting one side of each turbulence structure 211 to be vertical, it obstructs and disturbs part of the backflow, and in turn, it can also generate a certain disturbance on the lower side of the mainstream in the mainstream channel structure 1, which is more conducive to the backflow being mixed into the mainstream through the turbulence structures 211, effectively improving the mixing effect.

[0071] Furthermore, by setting the interval between adjacent turbulence structures 211 to be greater than the thickness of the turbulence structure 211, the intrusion of the recirculation into the mainstream is more effectively promoted. This allows the amount of recirculation entering the mainstream to promote the combustion efficiency and performance of the entire combustion chamber. If the interval is too small, the amount of recirculation entering the mainstream will be too small, causing the combustion chamber to fail to achieve optimal performance. If the interval is too large, the amount of recirculation entering the mainstream will be too large, affecting the mainstream of the combustion chamber and thus impacting the combustion efficiency and performance of the combustion chamber.

[0072] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, it further includes an ignition device 3. In this embodiment, a mounting position for mounting the ignition device 3 is provided on the bottom wall 23 of the cavity, and the ignition device 3 is installed in the mounting position by embedding to achieve installation with the bottom wall 23 of the cavity. In this embodiment, the ignition device 3 can be a shaped spark plug, a solid igniter, or other reusable igniter. In this embodiment, the ignition device 3 is located between the front edge 21 of the cavity and the front end of the fuel supply structure 22a. Of course, when the incoming Mach number is high, the ignition device can be omitted by modifying the powder fuel design and adding highly active combustion to the powder fuel, or a lifting mechanism can be used to retract the ignition device 3 below the surface of the bottom wall 23 of the cavity to reduce the impact on the airflow.

[0073] Combination Figure 1 , Figure 2 and Figure 3As shown, according to one embodiment of the present invention, it further includes: a protective structure 4; in this embodiment, the protective structure 4 is fixed on the bottom wall 23 of the cavity and adjacent to the ignition device 3; wherein, the protective structure 4 is disposed on the side opposite to the front end of the ignition device 3 and the fuel supply structure 22a. In this embodiment, the protective structure 4 has a columnar structure, with a first arc surface on the side adjacent to the ignition device 3 and a second arc surface on the side opposite to the fuel supply structure 22a. Through the above arrangement, the protective structure 4 is a curved structure that partially surrounds the ignition device 3. Of course, in another embodiment, when the ignition device 3 can be retracted, a lifting mechanism corresponding to the protective structure 4 can be further provided to retract the protective structure 4, or a flipping structure can be provided for the protective structure 4 to flip the protective structure 4 and shield the ignition device 3, so as to reduce the height reduction of the protective structure 4 or eliminate the influence on the airflow.

[0074] With the above-mentioned configuration, the airflow on the side adjacent to the ignition device 3 and the fuel supply structure 22a can be effectively blocked by the protective structure 4, so that a low-speed ignition zone can be formed around the ignition device 3, which effectively ensures the ignition effect of the present invention. At the same time, it can also play a good protective role for the ignition device 3.

[0075] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the fuel supply structure 22a is integrally formed with the cavity structure 2. This arrangement effectively ensures the reliability and consistency of the structure among the fuel supply structure 22a, the cavity bottom wall 23, the cavity rear edge 22, and the cavity side wall 24, which is beneficial to ensuring the stable operation of the entire combustion chamber.

[0076] Combination Figure 1 , Figure 2 and Figure 3 As shown, according to one embodiment of the present invention, the upper sidewall of the fuel supply structure 22a is a planar structure.

[0077] To further illustrate this solution, the workflow of this invention will be further explained.

[0078] The working process of the active recirculation chamber is described as follows: the fluidizing gas carries the powdered fuel and is supplied into the concave structure 2 from the fuel supply structure 22a at the bottom of the rear edge of the concave chamber. It cuts into the active recirculation zone B along the flow direction and mixes with the oxidant (which comes from the air in the mainstream) and exchanges energy and momentum. The ignition device 3 near the front edge 21 of the concave chamber ignites the powdered fuel. The mixed two-phase flow of the powdered fuel and the gas in the concave structure 2 is cut into the mainstream air d under the action of the turbulence structure 211 at the front edge 21 of the concave chamber. It is further burned in the mainstream region C and the shear region D. The fuel and combustion products in the shear region D enter the passive recirculation zone a for further combustion or to provide a high-temperature region for the active recirculation chamber.

[0079] The above description is merely an example of a specific solution of the present invention. For any devices and structures not described in detail herein, it should be understood that they are implemented using common devices and methods already available in the art.

[0080] The above description is merely one embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A powered return flow combustion chamber for a powder scramjet engine, characterized by, include: Main channel structure (1), and cavity structure (2) connected to the main channel structure (1). The cavity structure (2) includes: a front edge (21), a rear edge (22), a bottom wall (23), and a side wall (24). The rear edge of the cavity (22) is provided with a fuel supply structure (22a) that connects the front and rear sides of the rear edge of the cavity (22) and is used for powder fuel supply. The extension direction of the hollow channel (22a1) of the fuel supply structure (22a) is parallel to the bottom wall (23) of the cavity; The lower wall of the hollow channel (22a1) is flush with the inner side of the bottom wall (23) of the concave cavity; The hollow channel (22a1) has a regular opening at the front end of the channel facing the front edge (21) of the cavity, with a length greater than its width, and the length direction of the front end opening of the channel is parallel to the bottom wall (23) of the cavity.

2. The actively-refluxing combustion chamber of a powder scramjet engine of claim 1, wherein, The hollow channel (22a1) has a channel section (22a11) with a constant cross-section. The equal-section channel portion (22a11) starts from the opening at the front end of the channel and extends in a direction away from the opening at the front end of the channel.

3. The active recirculation combustion chamber of the powder scramjet engine according to claim 2, characterized in that, The extension length of the equal cross-section channel portion (22a11) is greater than the length of the opening at the front end of the channel.

4. The active recirculation combustion chamber of the powder scramjet engine according to claim 3, characterized in that, The fuel supply structure (22a) is arranged so that the front end of the cavity front edge (21) is flush with the inner wall of the cavity rear edge (22).

5. The actively-refluxing combustion chamber of a powder scramjet engine of claim 3, wherein, The fuel supply structure (22a) extends into the hollow cavity of the cavity structure (2) toward the front end of the cavity leading edge (21).

6. The actively-refluxing combustion chamber of a powder scramjet engine according to claim 4 or 5, characterized in that, The cavity front edge (21) is provided with a turbulence structure (211). The turbulence structure (211) is plate-shaped and is arranged perpendicular to the front edge (21) of the cavity; The upper edge of the turbulence structure (211) is flush with the inner lower wall of the main channel structure (1), or the upper edge of the turbulence structure (211) is lower than the inner lower wall of the main channel structure (1).

7. The active recirculation combustion chamber of the powder scramjet engine according to claim 6, characterized in that, On the leading edge (21) of the cavity, there are multiple perturbation structures (211) arranged at intervals; The arrangement direction of the plurality of the disturbance structures (211) is consistent with the length direction of the opening at the front end of the hollow channel (22a1).

8. The actively-refluxing combustion chamber of a powder scramjet engine of claim 7, wherein, Along the flow direction, the angle between the front edge (21) of the cavity and the inner lower wall is between 30° and 60°.

9. The active recirculation combustion chamber of the powder scramjet engine according to claim 8, characterized in that, Also includes: Ignition device (3); The ignition device (3) is embedded in the bottom wall (23) of the cavity; The ignition device (3) is located between the front edge (21) of the cavity and the front end of the fuel supply structure (22a).

10. The actively-refluxing combustion chamber of a powder scramjet engine of claim 9, wherein, Also includes: Protective structure (4); The protective structure (4) is fixed on the bottom wall (23) of the cavity and is adjacent to the ignition device (3); The protective structure (4) is located on the side opposite to the front end of the ignition device (3) and the fuel supply structure (22a); The fuel supply structure (22a) is integrally formed with the cavity structure (2).

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