Adjustable fuel injection branch plate structure of round cross-section flow channel ramjet engine and control method

Abstract

The application provides a circular cross-section flow channel ramjet engine adjustable oil injection support plate structure and a control method, and relates to the technical field.The circular cross-section flow channel ramjet engine adjustable oil injection support plate structure comprises an adjustable support plate unit and a driving assembly;an inner wall of an inner flow wall surface is provided with a plurality of grooves;the adjustable support plate unit comprises a plurality of rotating shafts and a plurality of arc-shaped support plates, the rotating shafts are rotationally installed on the inner flow wall surface and the axial directions of the rotating shafts are parallel to the axis of the inner flow wall surface, the arc-shaped support plates are installed at the ends of the rotating shafts, and the plurality of arc-shaped support plates are arranged in an array along the circumference of the inner flow wall surface; the driving assembly comprises a plurality of driving motors which are drivingly connected with the rotating shafts, and the plurality of driving motors synchronously act. Through the synchronous action of the plurality of driving motors, the rotating shafts drive the arc-shaped support plates to rotate, the structure is simple, and the response speed is relatively fast; the arc-shaped support plates are designed in a rear-swept strip shape and are provided with sharp leading edges, so that the air resistance and the aerodynamic loss can be reduced; the arc-shaped support plates can be accommodated into the grooves, the air resistance is reduced, and the overall thermal protection is facilitated.

Description

Technical Field

[0001] This invention relates to the field of aerospace engine technology, and in particular to an adjustable fuel injection support structure and control method for a circular cross-section flow channel ramjet engine. Background Technology

[0002] Future horizontal takeoff and landing aerospace vehicles need to operate in an extremely wide range, from zero speed to hypersonic speed and from ground to low Earth orbit, requiring propulsion systems with both high specific impulse and high thrust-to-weight ratio. A combined propulsion system based on turbines, rockets, and ramjet engines is an inevitable trend, with large-scale ramjet engines requiring Mach 2 to 10 or higher being the key to their development.

[0003] Ramjet engines use air as an oxidizer and generate thrust through fuel injection, mixing, and combustion. Delivering fuel to the core mainstream and efficiently mixing it with air is a key challenge for wide-range operation. Typically, ramjet engine fuel injection employs two main methods: direct injection near the wall and injection into the mainstream via an insert structure. Due to bottlenecks such as insufficient penetration depth and limited mixing and diffusion range in near-wall direct injection, practical large-scale ramjet engines primarily utilize insert structures such as fuel injector plates to deliver fuel to the core mainstream for mixing.

[0004] Existing fuel injection support plate structures mostly use linkage transmission mechanisms to achieve support plate movement, resulting in complex mechanical structures and limited response speed of the fuel injection support plate. While the support plate structure undertakes the function of fuel injection, it also creates flow around and obstructs the high-speed incoming flow. On the one hand, this is beneficial for enhancing fuel-air mixing, but on the other hand, it also brings aerodynamic losses and reduces the main flow work capacity. Excessive losses can cause a significant decline in engine performance. The support plate structure is generally thin, flat, and slender. Under the dual effects of convection and radiation heat transfer, the thermal environment of its leading edge stagnation point and structural surface is very harsh, which can easily cause heat sink structure ablation and damage or increase the need for active cooling. Summary of the Invention

[0005] In view of this, the present invention proposes an adjustable fuel injection support plate structure and control method for a circular cross-section flow channel ramjet engine, in order to solve the technical problems mentioned in the background art, which are that the existing solutions mostly use linkage transmission mechanisms to realize the movement of the support plate, resulting in complex mechanical structures and limited response speed of the fuel injection support plate; the resistance of the support plate leads to large aerodynamic losses; and the structure has poor thermal protection.

[0006] The technical solution of this invention is implemented as follows: In a first aspect, the present invention provides an adjustable fuel injection support structure for a circular cross-section flow channel ramjet engine, comprising an adjustable support unit and a drive assembly disposed on the inner flow wall of the combustion chamber, wherein: The inner wall of the inner flow wall is provided with multiple grooves; The adjustable support plate unit includes multiple rotating shafts and multiple arc-shaped support plates. The rotating shafts are rotatably mounted on the inner flow wall and their axial direction is parallel to the axis of the inner flow wall. The arc-shaped support plates are mounted at the ends of the rotating shafts. The arc-shaped support plates have a swept-back strip design and a sharp leading edge. The multiple arc-shaped support plates are arranged in a circumferential array along the inner flow wall. The arc-shaped support plates can be stored in the groove. The drive assembly includes multiple drive motors, which are drivenly connected to the rotating shaft, and the multiple drive motors operate synchronously.

[0007] In some alternative implementations, preferably, the plurality of said arc-shaped support plates are arranged symmetrically after being fully extended.

[0008] In some alternative embodiments, preferably, the curvature of the arc-shaped support plate is designed to match the curvature of the combustion chamber, so that after the arc-shaped support plate is housed in the groove, the outer edge of the arc-shaped support plate is flush with the inner flow wall surface.

[0009] In some optional embodiments, preferably, the arc-shaped support plate has a medium flow channel inside, and the end of the arc-shaped support plate facing the spray area has an oil injection hole that connects to the medium flow channel. The rotating shaft also has a connecting channel that connects the medium flow channel and the external oil supply system.

[0010] In some optional embodiments, preferably, the connecting channel is also connected to the gas tank built into the ramjet engine via a hose. The connecting channel is equipped with an oil valve on the pipeline connecting to the external oil supply system, and the hose is equipped with an air valve. When the support plate is in a non-injection state, the air valve is turned on and the oil valve is turned off, and the gas carried by the ramjet engine is used for injection cooling to form thermal protection.

[0011] In some optional embodiments, preferably, a controller and an angle sensor are also included. The angle sensor is mounted on the arc-shaped support plate and is used to measure the actual rotation angle of the arc-shaped support plate and send it to the controller. The controller is used to control multiple drive motors to rotate and to control them through PID closed-loop control. By comparing the actual rotation angle of the arc-shaped support plate with the target value, the input electrical signal is continuously adjusted so that the arc-shaped support plate accurately reaches the target position.

[0012] In a second aspect, the present invention provides a control method for an adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine as described in the first aspect, comprising: The operating status and operating mode of the engine combustion chamber are determined based on the aircraft's flight status, and the fuel supply requirements of the combustion chamber are further determined. The working requirements of the arc-shaped support plate are determined based on the fuel supply requirements. The working requirements of the arc-shaped support plate include structural adjustment requirements and supply control requirements. The penetration height h of the combustion chamber wall is determined according to the structural adjustment requirements, and converted into the rotation angle of the support plate corresponding to the current required penetration height h through the support plate motion model. The rotation of the arc-shaped support plate is completed by driving the motor to rotate. The oil circuit valve is controlled according to the supply control requirements to complete the injection action.

[0013] In some optional implementations, preferably, the support plate motion model is as follows: Calculate the intermediate length L2 based on the rotation angle β of the support plate, the length L of the support plate, the distance L1 between the center of the rotating shaft and the inner wall of the combustion chamber, the radius r of the inner wall of the combustion chamber, and the angle θ between the arc-shaped support plate and the tangent of the concentric circle containing the center of the rotating shaft when the support plate is placed in the groove. Based on the fact that the sum of the infiltration height h of the combustion chamber wall and the intermediate length L2 is equal to the sum of the distance L1 between the center of the rotating shaft and the combustion chamber wall surface and the radius r of the combustion chamber wall, the relationship between the rotation angle β of the support plate and the infiltration height h of the combustion chamber wall is established.

[0014] In some optional implementations, preferably, the operating state and operating mode of the engine combustion chamber are determined based on the aircraft's flight status, and the combustion chamber fuel supply requirements are further determined, including: The engine thrust F was calculated using the flight Mach number Ma, flight altitude H, and angle of attack α, combined with the propellant mass flow rate. Calculate engine specific impulse I sp ; Through engine thrust F and engine specific impulse I sp Calculate the combustion efficiency η along the engine path comb And through the engine's combustion efficiency η along the path comb Calculate the required fuel-to-fuel mixture efficiency η for the current engine. comb，demand ; The required fuel-to-fuel mixing efficiency η for the current engine comb，demand Calculate the infiltration height h of the combustion chamber wall and the required fuel injection equivalence ratio ER.

[0015] In some optional embodiments, preferably, the method further includes: when the arc-shaped support plate is in the closed state, closing the fuel supply valve and opening the gas path valve to inject nitrogen for cooling; and calculating the required nitrogen injection flow rate ratio based on the engine flow direction distance x from the fuel injection point, the cooling requirement ΔT, the flight Mach number Ma, the flight altitude H, and the flight angle of attack α. .

[0016] The adjustable fuel injection support plate structure and control method for a circular cross-section flow channel ramjet engine of the present invention have the following advantages over the prior art: (1) By synchronously operating multiple drive motors, the rotating shaft drives the arc-shaped support plate to rotate. The structure is simple and the arc-shaped support plate has a fast response speed. The arc-shaped support plate has a swept-back strip design and a sharp leading edge, which can reduce airflow resistance and thus reduce aerodynamic losses. When the arc-shaped support plate is retracted, it is located in the groove, which reduces airflow resistance and is also beneficial for overall thermal protection. (2) The curvature of the arc-shaped support plate is matched with the curvature of the combustion chamber so that after the arc-shaped support plate is housed in the groove, the outer edge of the arc-shaped support plate is flush with the inner flow wall, which reduces airflow resistance and is beneficial to overall thermal protection. (3) The arc-shaped support plate has a medium flow channel inside, and the end of the arc-shaped support plate facing the injection area has an oil injection hole that connects to the medium flow channel. The rotating shaft also has a connecting channel connecting the medium flow channel and the external oil supply system. The rotating shaft can also act as an oil supply pipe. The groove can play a role in stabilizing the flame and enhancing combustion while accommodating the arc-shaped support plate. The overall structure is compact and the arc-shaped support plate has high adjustment response efficiency. (4) The gas tank built into the ramjet engine is also connected through the connecting channel via a hose. The connecting channel is equipped with an oil valve on the pipeline connecting to the external oil supply system, and the hose is equipped with an air valve. When the support plate is in a non-injection state, the air valve is turned on and the oil valve is turned off, and the gas carried by the ramjet engine is used for injection cooling to form thermal protection. (5) Calculate the intermediate length L2 based on the rotation angle β of the support plate, the length L of the support plate, the distance L1 between the center of the rotating shaft and the inner wall of the combustion chamber, the radius r of the inner wall of the combustion chamber, and the angle θ between the arc-shaped support plate and the tangent of the concentric circle containing the center of the rotating shaft when it is placed in the groove. Based on the fact that the sum of the penetration height h of the inner wall of the combustion chamber and the intermediate length L2 is equal to the sum of the distance L1 between the center of the rotating shaft and the inner wall of the combustion chamber and the radius r of the inner wall of the combustion chamber, establish the relationship between the rotation angle β of the support plate and the penetration height h of the inner wall of the combustion chamber, thereby constructing the motion model of the support plate. This method is simple and reliable, with less calculation, and can accurately obtain the rotation angle of the support plate, so that the adjustment amount can be calculated based on the current support plate angle. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the adjustable fuel injection support plate structure of the circular cross-section flow channel ramjet engine in an embodiment of the present invention; Figure 2This is a schematic diagram of the adjustable support plate unit and drive assembly in an embodiment of the present invention; Figure 3 This is a schematic diagram of the arc-shaped support plate in its fully open state in an embodiment of the present invention; Figure 4 This is a schematic diagram of the arc-shaped support plate in its fully closed state in an embodiment of the present invention; Figure 5 This is a flowchart illustrating the control method of the adjustable fuel injection support plate structure of the circular cross-section flow channel ramjet engine in an embodiment of the present invention. Figure 6 This is a schematic diagram illustrating the geometric relationship of constructing the motion model of the support plate in the control method of the adjustable fuel injection support plate structure of the circular cross-section flow channel ramjet engine in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached drawings: 1-Inner flow wall, 2-Adjustable support plate unit, 3-Drive assembly; 11-groove; 21-Rotating shaft, 22-Arc-shaped support plate; 31-Drive motor. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0021] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention based on the specific circumstances.

[0022] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of 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, they should not be construed as limitations on the embodiments of the present invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying 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 this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0025] The following disclosure provides numerous different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. Additionally, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0026] The technical solution will now be explained in detail: Reference Figures 1-4 As shown, a first aspect of the present invention provides an adjustable fuel injection support structure for a circular cross-section flow channel ramjet engine, comprising an adjustable support unit 2 and a drive assembly 3 disposed on the inner flow wall 1 of the combustion chamber, wherein: The inner wall of the inner flow wall 1 is provided with a plurality of grooves 11; the two ends of the grooves 11 are not in the same radial end face, and the plurality of grooves 11 are spread out in a petal shape. For example, in this embodiment, there are 6 grooves 11, and the central angle corresponding to the projection of the grooves 11 on the radial end face is less than 60 degrees, so that the structure will not break, the integrity is good, and there will be no interference when the arc-shaped support plate 22 rotates. The adjustable support plate unit 2 includes multiple rotating shafts 21 and multiple arc-shaped support plates 22. The rotating shafts 21 are rotatably mounted on the inner flow wall 1 with their axial direction parallel to the axis of the inner flow wall 1. The arc-shaped support plates 22 are mounted at the ends of the rotating shafts 21. The arc-shaped support plates 22 have a swept-back strip design and a sharp leading edge. Multiple arc-shaped support plates 22 are arranged in a circumferential array along the inner flow wall 1. The arc-shaped support plates 22 can be stored in the groove 11. The rotating shafts 21 rotate under the driving action, thereby driving the arc-shaped support arm to rotate around the axis of the rotating shafts 21, realizing the switching between the two states of the arc-shaped support plates 22 from fully open to fully closed. The drive assembly 3 includes multiple drive motors 31, which are driven and connected to the rotating shaft 21. The multiple drive motors 31 operate synchronously. The forward and reverse rotation of the drive motors 31 enables the arc-shaped support plate 22 to rotate in both directions, thus switching between the two states of the arc-shaped support plate 22. The extreme positions at both ends can be controlled by the stroke of the drive motors 31, which is relatively simple and reliable.

[0027] The adjustable fuel injection support plate structure for the circular cross-section flow channel ramjet engine proposed in this embodiment drives the rotating shaft 21 to rotate the arc-shaped support plate 22 through the synchronous operation of multiple drive motors 31. The structure is simple and the arc-shaped support plate 22 has a fast response speed. The arc-shaped support plate 22 has a swept-back strip design and a sharp leading edge, which can reduce airflow resistance and thus reduce aerodynamic losses. When the arc-shaped support plate 22 is retracted, it is located in the groove 11, which reduces airflow resistance and is also beneficial for overall thermal protection.

[0028] In some embodiments, the plurality of arc-shaped support plates 22 are arranged symmetrically after being fully deployed. The symmetrical arrangement of the arc-shaped support plates 22 can make the overall structure uniformly stressed and the shear forces cancel each other out, which can improve the service life of the device.

[0029] In some embodiments, the curvature of the arc-shaped support plate 22 is designed to match the curvature of the combustion chamber, so that after the arc-shaped support plate 22 is housed in the groove 11, the outer edge of the arc-shaped support plate 22 is flush with the inner flow wall 1. This structural design reduces airflow resistance and improves overall thermal protection.

[0030] In some embodiments, the arc-shaped support plate 22 has a medium flow channel inside, and one end of the arc-shaped support plate 22 facing the injection area has an oil injection hole connecting the medium flow channel. The rotating shaft 21 also has a connecting channel connecting the medium flow channel and the external oil supply system. The rotating shaft 21 can also serve as an oil supply pipe. The groove 11, while accommodating the arc-shaped support plate 22, can also play a role in stabilizing the flame and enhancing combustion. The overall structure is compact, and the arc-shaped support plate 22 has high adjustment response efficiency.

[0031] In some embodiments, the connection channel is also connected to the gas tank built into the ramjet engine via a hose. The pipeline connecting the connection channel to the external fuel supply system is equipped with an oil valve, and the hose is equipped with an air valve. When the support plate is in a non-fuel injection state, the air valve is turned on and the oil valve is turned off, and the gas carried by the ramjet engine is used for injection cooling to form thermal protection.

[0032] In some embodiments, the adjustable fuel injection support plate structure of the circular cross-section flow channel ramjet engine further includes a controller and an angle sensor. The angle sensor is installed on the arc-shaped support plate 22 and is used to measure the actual rotation angle of the arc-shaped support plate 22 and send it to the controller. The controller is used to control multiple drive motors 31 to rotate and control them through PID closed-loop control. By comparing the actual rotation angle of the arc-shaped support plate 22 with the target value, the input electrical signal is continuously adjusted so that the arc-shaped support plate 22 accurately reaches the target position.

[0033] Based on the same concept, a second aspect of the present invention, combined with... Figure 5 and Figure 6 As shown, a control method for an adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine, as described in the first aspect embodiment, is provided, comprising: Step S1: Determine the operating status and operating mode of the engine combustion chamber based on the aircraft's flight status, and further determine the combustion chamber fuel supply requirements; Step S2: Determine the working requirements of the arc-shaped support plate 22 according to the fuel supply requirements. The working requirements of the arc-shaped support plate 22 include structural adjustment requirements and supply control requirements. Step S3: Determine the infiltration height h of the combustion chamber wall according to the structural adjustment requirements, and convert it into the rotation angle of the support plate corresponding to the current required infiltration height h through the support plate motion model. The rotation of the arc support plate 22 is completed by driving the motor 31 to rotate. The oil circuit valve is controlled according to the supply control requirements to complete the injection action.

[0034] In some embodiments, the process of constructing the support plate motion model in step S3 is as follows: Based on the rotation angle β of the support plate, the length L of the support plate, the distance L1 between the center of the rotating shaft 21 and the inner wall of the combustion chamber, the radius r of the inner wall of the combustion chamber, and the angle θ between the arc-shaped support plate 22 and the tangent of the concentric circle containing the center of the rotating shaft 21 when it is placed in the groove 11, the intermediate length L2 is calculated; the specific calculation formula is as follows: (1); In formula (1), L2 is the middle length, r is the radius of the inner wall of the combustion chamber, L1 is the distance between the center of the rotating shaft 21 and the inner wall of the combustion chamber, L is the length of the support plate, θ is the angle between the arc-shaped support plate 22 and the tangent of the concentric circle containing the center of the rotating shaft 21 when the arc-shaped support plate 22 is placed in the groove 11, and β is the rotation angle of the support plate. Based on the fact that the sum of the combustion chamber wall penetration height h and the intermediate length L2 is equal to the sum of the distance L1 between the center of the rotation axis 21 and the combustion chamber wall surface and the radius r of the combustion chamber wall, a relationship is established between the support plate rotation angle β and the combustion chamber wall penetration height h. The following formula can be obtained from the geometric relationship: (2); In equation (2), h is the infiltration height of the combustion chamber wall; Combining equations (1) and (2), we can obtain the following formula: (3); After establishing the connection, the rotation angle β is determined based on the current required permeability height h using the model described above, and the adjustment amount Δβ is calculated in conjunction with the current angle β0. The calculation formula is as follows: (4).

[0035] In some embodiments, step S1 involves determining the operating state and operating mode of the engine combustion chamber based on the aircraft's flight status, and further determining the combustion chamber fuel supply requirements, including: The engine thrust F was calculated using the flight Mach number Ma, flight altitude H, and angle of attack α, combined with the propellant mass flow rate. Calculate engine specific impulse I sp The calculation formula is as follows: (5); In equation (5), F is the engine thrust, Mach number Ma is the flight Mach number, H is the flight altitude, α is the flight angle of attack, and f2 is the corresponding functional relationship; (6); In equation (6), I sp For the engine's specific impulse. where g is the mass flow rate and g is the acceleration due to gravity. Through engine thrust F and engine specific impulse I sp Calculate the combustion efficiency η along the engine path comb And through the engine's combustion efficiency η along the path comb Calculate the required fuel-to-fuel mixture efficiency η for the current engine. mix，demand Engine combustion efficiency η comb The calculation formula is as follows: (7); In equation (7), f4 is η comb With F and I sp The corresponding functional relationship; The required fuel-to-fuel mixing efficiency η for current engines mix，demand The calculation formula is as follows: (8); In equation (8), f5 is η comb With η mix，demand The corresponding functional relationship; The required fuel-to-fuel mixing efficiency η for the current engine comb，demand Calculate the combustion chamber wall penetration height h and the required fuel injection equivalence ratio ER. The specific formula is as follows: (9); In equation (9), f6 represents h and ER and η. mix，demand The corresponding functional relationship.

[0036] In some embodiments, the method further includes: when the arc-shaped support plate 22 is in the closed state, closing the fuel supply valve and opening the gas path valve to inject nitrogen for cooling; and calculating the required nitrogen injection flow rate ratio based on the engine flow direction distance x from the fuel injection point, the cooling requirement ΔT, the flight Mach number Ma, the flight altitude H, and the flight angle of attack α. Required nitrogen injection flow rate ratio The calculation formula is as follows: (10); In equation (10), x is the distance from the fuel injection point to the engine flow direction, ΔT is the cooling requirement, and f7 is... The functional relationships between x, ΔT, Ma, H, and α.

[0037] In some embodiments, in step S3, the rotation of the arc-shaped support plate 22 is completed by rotating the drive motor 31. Specifically, this includes: the drive motor 31 rotates and is controlled in a closed loop using PID control, the principle of which is as follows: Figure 5 As shown, by measuring the actual rotation angle of the arc-shaped support plate 22 and comparing it with the target value, the input electrical signal is continuously adjusted so that the support plate accurately reaches the target position.

[0038] The adjustable fuel injection support plate structure and control method for a circular cross-section flow channel ramjet engine proposed in this invention have the following advantages: (1) The present invention has an array-type layout feature, which can be flexibly designed according to the configuration features of the engine combustion chamber to meet the requirements of fuel blending and spatial distribution, and can be driven and controlled by the same fuel supply system; (2) The present invention has a wide adaptability adjustable working mode. The arc-shaped support plate 22 can be adjusted according to the flow velocity, temperature and fuel injection requirements in the combustion chamber of the engine. When injection is not required, all arc-shaped support plates 22 can be completely retracted, reducing the obstruction loss of high-speed airflow on the wall and structural ablation. (3) The present invention optimizes the overall design of the adjustable support plate structure. The rotating shaft 21 can also serve as an oil pipeline. The groove 11 can play a role in stabilizing the flame and enhancing combustion while accommodating the arc-shaped support plate 22. The overall structure is compact and the arc-shaped support plate 22 has high adjustment response efficiency. (4) The arc-shaped support plate 22 in this invention is designed with specific considerations for flow resistance and thermal protection. Based on the adjustability of the arc-shaped support plate 22, the arc-shaped support plate 22 is designed with a large sweep angle and a sharp leading edge to reduce airflow resistance. The degree of curvature of the arc-shaped support plate 22 is matched with the local curvature of the circular cross-section combustion chamber, so that when the arc-shaped support plate 22 is retracted, it can be flush with the combustion chamber wall, reducing airflow resistance and facilitating overall thermal protection. (5) The arc-shaped support plate 22 structure in this invention has a large-scale swirling mixing aerodynamic effect. Combined with the windward inclined surface design and surface staggered structure design on both sides of the support plate, it can fully realize macroscopic large-scale and local microscopic small-scale mixing enhancement, which is conducive to achieving efficient fuel mixing over short distances.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine, characterized in that, Includes an adjustable support plate unit and a drive assembly disposed on the inner flow wall of the combustion chamber, wherein: The inner wall of the inner flow wall is provided with multiple grooves; The adjustable support plate unit includes multiple rotating shafts and multiple arc-shaped support plates. The rotating shafts are rotatably mounted on the inner flow wall and their axial direction is parallel to the axis of the inner flow wall. The arc-shaped support plates are mounted at the ends of the rotating shafts. The arc-shaped support plates have a swept-back strip design and a sharp leading edge. The multiple arc-shaped support plates are arranged in a circumferential array along the inner flow wall. The arc-shaped support plates can be stored in the groove. The drive assembly includes multiple drive motors, which are drivenly connected to the rotating shaft, and the multiple drive motors operate synchronously.

2. The adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine as described in claim 1, characterized in that, When the multiple arc-shaped support plates are fully extended, they are arranged symmetrically.

3. The adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine as described in claim 1, characterized in that, The curvature of the arc-shaped support plate is designed to match the curvature of the combustion chamber, so that after the arc-shaped support plate is housed in the groove, the outer edge of the arc-shaped support plate is flush with the inner flow wall.

4. The adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine as described in claim 1, characterized in that, The arc-shaped support plate has a medium flow channel inside, and the end of the arc-shaped support plate facing the spray area has an oil injection hole that connects to the medium flow channel. The rotating shaft also has a connecting channel that connects the medium flow channel and the external oil supply system.

5. The adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine as described in claim 4, characterized in that, The connection channel is also connected to the gas tank built into the ramjet engine via a hose. The pipeline connecting the connection channel to the external fuel supply system is equipped with an oil valve, and the hose is equipped with a gas valve. When the support plate is in a non-fuel injection state, the gas valve is turned on and the oil valve is turned off, and the gas carried by the ramjet engine is used for injection cooling to form thermal protection.

6. The adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine as described in claim 1, characterized in that, It also includes a controller and an angle sensor. The angle sensor is installed on the arc-shaped support plate and is used to measure the actual rotation angle of the arc-shaped support plate and send it to the controller. The controller is used to control multiple drive motors to rotate and to control them through PID closed-loop control. By comparing the actual rotation angle of the arc-shaped support plate with the target value, the input electrical signal is continuously adjusted so that the arc-shaped support plate can accurately reach the target position.

7. A control method for an adjustable fuel injection support plate structure for a circular cross-section flow channel ramjet engine as described in any one of claims 1 to 6, characterized in that, include: The operating status and operating mode of the engine combustion chamber are determined based on the aircraft's flight status, and the fuel supply requirements of the combustion chamber are further determined. The working requirements of the arc-shaped support plate are determined based on the fuel supply requirements. The working requirements of the arc-shaped support plate include structural adjustment requirements and supply control requirements. The penetration height h of the combustion chamber wall is determined according to the structural adjustment requirements, and converted into the rotation angle of the support plate corresponding to the current required penetration height h through the support plate motion model. The rotation of the arc-shaped support plate is completed by driving the motor to rotate. The oil circuit valve is controlled according to the supply control requirements to complete the injection action.

8. The control method for the adjustable fuel injection support plate structure of the circular cross-section flow channel ramjet engine as described in claim 7, characterized in that, The motion model of the support plate is as follows: Calculate the intermediate length L2 based on the rotation angle β of the support plate, the length L of the support plate, the distance L1 between the center of the rotating shaft and the inner wall of the combustion chamber, the radius r of the inner wall of the combustion chamber, and the angle θ between the arc-shaped support plate and the tangent of the concentric circle containing the center of the rotating shaft when the support plate is placed in the groove. Based on the fact that the sum of the infiltration height h of the combustion chamber wall and the intermediate length L2 is equal to the sum of the distance L1 between the center of the rotating shaft and the combustion chamber wall surface and the radius r of the combustion chamber wall, the relationship between the rotation angle β of the support plate and the infiltration height h of the combustion chamber wall is established.

9. The control method for the adjustable fuel injection support plate structure of the circular cross-section flow channel ramjet engine as described in claim 7, characterized in that, The operating status and operating mode of the engine combustion chamber are determined based on the aircraft's flight conditions, and the fuel supply requirements for the combustion chamber are further determined, including: The engine thrust F was calculated using the flight Mach number Ma, flight altitude H, and angle of attack α, combined with the propellant mass flow rate. Calculate engine specific impulse I sp ; Through engine thrust F and engine specific impulse I sp Calculate the combustion efficiency η along the engine path comb And through the engine's combustion efficiency η along the path comb Calculate the required fuel-to-fuel mixture efficiency η for the current engine. comb，demand ; The required fuel-to-fuel mixing efficiency η for the current engine comb，demand Calculate the infiltration height h of the combustion chamber wall and the required fuel injection equivalence ratio ER.

10. The control method for the adjustable fuel injection support plate structure of the circular cross-section flow channel ramjet engine as described in claim 7, characterized in that, Also includes: When the arc-shaped support plate is in the closed state, the fuel supply valve is closed and the gas path valve is opened to inject nitrogen for cooling. The required nitrogen injection flow rate ratio is calculated based on the engine flow direction distance x from the fuel injection point, the cooling requirement ΔT, the flight Mach number Ma, the flight altitude H, and the flight angle of attack α. .

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