Wide operational range grid fin integrated with shock control structure

Abstract

The application relates to the field of aerospace technology, in particular to a wide working domain grid fin integrated with a shock control structure, which comprises an external frame and a plurality of wing elements located in the external frame, the inside of the side wall of each wing element is provided with a pressure stabilization cavity and a ventilation cavity in communication with the pressure stabilization cavity, the pressure stabilization cavity is close to the opening of the wing element, and the ventilation cavity is close to the bottom of the wing element; the left and right wall surfaces of the side wall of each wing element are provided with a bleed air area and an exhaust area, the bleed air area is located at the leading edge of the wing element, the exhaust area is located at the bottom of the wing element, the left and right wall surfaces of the side wall of each wing element are provided with bleed air holes in communication with the bleed air area and the pressure stabilization cavity, and the left and right wall surfaces of the side wall of each wing element are provided with exhaust holes in communication with the exhaust area and the ventilation cavity. The application can widen the working speed domain, improve the transonic performance, expand the working attack angle range, enhance the maneuverability, reduce the flight resistance, improve the economy, and enhance the reliability of the structure and control.

Description

Technical Field

[0001] This application relates to the field of aerospace technology, and in particular to a wide-operating-domain grid rudder with an integrated shock wave control structure. Background Technology

[0002] A grid rudder, also known as a grid rudder or grid wing, is a flight control device consisting of an outer frame and internal wing elements arranged in a grid pattern. As a highly efficient aerodynamic control surface, it has advantages such as small folded size, high control efficiency when deployed, and good hinge torque characteristics.

[0003] Currently, grid fins are widely used in various aerospace vehicles, primarily for flight attitude control, stability control during stage separation, and aerodynamic deceleration and attitude adjustment during the return and landing of the first stage of reusable rockets. For example, the US Falcon 9 launch vehicle utilizes its deflectable titanium alloy grid fins to precisely control the flight trajectory and landing attitude of the first stage during its return from high altitude to the ground, making it one of the key technologies for achieving vertical rocket recovery.

[0004] In existing grid rudder designs, the internal airfoil elements are typically solid structures, generating control force by deflecting the grid rudder as a whole. Optimization of its aerodynamic performance mainly focuses on the macroscopic geometry of the grid rudder, such as using different airfoil profile shapes, changing the density of the grid, or designing a swept-back airfoil leading edge.

[0005] Despite the great success of existing grid rudder technology, its inherent structural form has also revealed some aerodynamic defects under certain flight conditions, limiting its operating range and performance: 1. Sharp Deterioration in Transonic Performance: When the flight Mach number is in the transonic region, strong shock waves easily form within the narrow channels of the grid rudder, causing airflow "blockage." This phenomenon causes the drag coefficient of the grid rudder to increase sharply, forming a huge "drag peak." At the same time, the control efficiency of the rudder surface deflection will be severely reduced or even completely lost, creating a control "blind spot." This is extremely detrimental to reentry missions that require precise control of energy and attitude throughout the entire flight.

[0006] 2. High wave drag at supersonic speeds: In specific supersonic ranges, the complex geometry of the grid fin generates a series of complex oblique and bow shock waves. These shock waves interfere with and reflect each other, forming the main source of drag—wave drag. Traditional solid structure designs struggle to fundamentally weaken these shock waves, resulting in a low lift-to-drag ratio at supersonic speeds.

[0007] 3. Limited control capability at high angle of attack: When the grid rudder operates at a large angle of attack, large-scale airflow separation is likely to occur on the wing element on its leeward side, resulting in a nonlinear decrease in lift (normal force) and a "stall" phenomenon. This weakens the control capability of the rudder surface and may even lead to unpredictable unsteady flutter due to asymmetric separation, endangering structural safety and flight stability.

[0008] In summary, existing grid rudder technology faces fundamental bottlenecks in expanding its operating speed range (especially the transonic range) and operating angle of attack range. Summary of the Invention

[0009] This application addresses the problems of shock wave blockage, high wave drag, and severe flow separation in existing grid rudders during transonic, supersonic, and high angle-of-attack flight. It proposes a wide-operating-domain grid rudder with an integrated shock wave control structure to solve the aforementioned technical problems.

[0010] To solve the above-mentioned technical problems, this application provides the following technical solution: A wide-operating-domain grid rudder with an integrated shock wave control structure includes: an outer frame and multiple wing elements located within the outer frame. Each wing element has a pressure-stabilizing cavity and a ventilation cavity communicating with the pressure-stabilizing cavity inside its sidewall. The pressure-stabilizing cavity is close to the opening of the wing element, and the ventilation cavity is close to the bottom of the wing element. The left and right walls of the sidewall of each wing element have an air intake area and an exhaust area. The air intake area is located at the leading edge of the wing element, and the exhaust area is located at the bottom of the wing element. Each wing element has an air intake hole communicating with the air intake area and the pressure-stabilizing cavity on its left and right walls, and an exhaust hole communicating with the exhaust area and the ventilation cavity on its left and right walls.

[0011] In the wide operating domain grid rudder of the integrated shock wave control structure described above, preferably, the air vents are inclined from the outside to the inside from the opening direction near the wing element to the opening direction away from the wing element, and the exhaust vents are inclined from the inside to the outside from the opening direction near the wing element to the opening direction away from the wing element.

[0012] In the wide operating domain grid fin of the integrated shock wave control structure described above, preferably, the width of the pressure stabilizing chamber is greater than the width of the ventilation chamber.

[0013] In the wide operating domain grid rudder of the integrated shock wave control structure described above, preferably, the pressure stabilizing cavity and ventilation cavity inside the sidewall of each wing element are independent of or interconnected with the pressure stabilizing cavity and ventilation cavity inside the sidewall of the adjacent wing element.

[0014] In the wide operating domain grid rudder of the integrated shock wave control structure described above, preferably, the pressure stabilizing cavity and ventilation cavity inside the sidewall of the wing element connected to the outer frame are interconnected with the pressure stabilizing cavity and ventilation cavity inside the sidewall of other wing elements through channels in the outer frame.

[0015] In the wide operating domain grid rudder of the integrated shock wave control structure described above, preferably, there is a certain interval between the bleed zone and the exhaust zone.

[0016] In the wide operating domain grid rudder of the integrated shock control structure described above, preferably, the exhaust port is located after the shock foot of the strong shock wave formed in the bleed zone, and the exhaust port is located before or within the separation zone in which flow separation is expected to occur in the exhaust zone.

[0017] In the wide operating domain grid rudder of the integrated shock wave control structure described above, preferably, the air vents on the left / right sidewall of each wing element are arranged in one / multiple rows, and the exhaust vents on the left / right sidewall of each wing element are arranged in one / multiple rows.

[0018] In the wide-operating-domain grid fin of the integrated shock wave control structure described above, preferably, the air intake and exhaust ports are through-holes at the micrometer or millimeter level.

[0019] In the wide-operating-domain grid rudder of the integrated shock wave control structure described above, preferably, the air intake is a circular hole, the exhaust is a slit-shaped hole, and the extension direction of the exhaust is the same as the direction in which the exhaust holes are arranged in a row.

[0020] The beneficial effects of this application are: 1. Structural Integration Innovation: For the first time, passive control structures such as air intake vents, exhaust vents, and internal cavities are organically integrated into a single grid rudder wing element, forming a complete and collaborative "air intake-pressure stabilization-exhaust" flow field control system.

[0021] 2. Passive adaptive mechanism: This application utilizes the pressure difference of the flow field itself to drive the airflow to exchange mass inside and outside the wing element of the grid fin, realizing passive and adaptive adjustment of shock waves and boundary layers. It does not require any external energy or complex control system and has high reliability.

[0022] 3. Functional composite design: The air intake at the leading edge of the wing element serves the dual purpose of weakening the shock wave and providing an air source for boundary layer control. The cavity inside the sidewall of the wing element serves the dual purpose of structural channel and flow field regulator. The exhaust port at the rear serves the dual purpose of releasing the pressure inside the cavity and injecting energy into the boundary layer.

[0023] 4. Complex internal flow channel design inside the wing element sidewall: The complex flow channel design inside the wing element sidewall in this application is a key feature that distinguishes it from the solid sidewall of the wing element in all existing technologies. Attached Figure Description

[0024] 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 recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0025] Figure 1 This is a front view of the basic configuration of the wide-operating-domain grid rudder of the integrated shock wave control structure; Figure 2 This is a three-dimensional diagram of the basic configuration of the wide-operating-domain grid fin of the integrated shock wave control structure; Figure 3 It is a three-dimensional diagram of the forward-swept configuration of the wide-operating-domain grid fins of the integrated shock wave control structure; Figure 4 This is a three-dimensional diagram of the basic configuration of the wing element of the wide-operating-domain grid rudder with integrated shock wave control structure; Figure 5 It is a three-dimensional view of the forward-swept configuration of the wing element of the wide-operating-domain grid rudder with integrated shock wave control structure; Figure 6 This is a schematic diagram of the wing element of a wide-operating-domain grid rudder with integrated shock wave control structure; Figure 7 This is a cross-sectional schematic diagram of the wing element of a wide-operating-domain grid rudder with an integrated shock wave control structure. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown 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 are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] like Figures 1 to 5 As shown, this application provides a wide-operating-domain grid rudder with an integrated shock wave control structure, including: an outer frame 10 and a plurality of wing elements 20 located within the outer frame 10; wherein, all wing elements 20 are lattices formed by staggered winglets located within the outer frame 10, and the opening of each wing element 20 faces the same side (upper or lower) of the outer frame 10. Optionally, all wing elements 20 within the outer frame 10 are arranged in rows and columns.

[0028] like Figure 6 and Figure 7As shown, each wing element 20 has a pressure stabilizing chamber 21 and a ventilation chamber 22 connected to the pressure stabilizing chamber 21 inside its side wall. The pressure stabilizing chamber 21 is close to the opening of the wing element 20 it is located in, and the ventilation chamber 22 is close to the bottom of the wing element 20 it is located in. The pressure stabilizing chamber 21 and the ventilation chamber 22 serve as static pressure chambers, which can receive and collect the airflow drawn in from the leading edge of the wing element 20, so that the pressure of the airflow in the chamber (pressure stabilizing chamber 21 and ventilation chamber 22) tends to be stable and uniform.

[0029] Optionally, the width of the pressure stabilizing chamber 21 is greater than the width of the ventilation chamber 22, so that the airflow pressure can be stabilized in a timely manner after being drawn into the pressure stabilizing chamber 21, and the airflow pressure can be made uniform in a timely manner. Alternatively, the pressure stabilizing chamber 21 and ventilation chamber 22 inside the sidewall of each wing element 20 can be independent of each other or interconnected with the pressure stabilizing chamber 21 and ventilation chamber 22 inside the sidewall of adjacent wing elements 20. Still optional, the pressure stabilizing chamber 21 and ventilation chamber 22 inside the sidewall of a wing element 20 connected to the outer frame 10 can be interconnected with the pressure stabilizing chamber 21 and ventilation chamber 22 inside the sidewall of other wing elements 20 through channels within the outer frame 10, in order to achieve a wider range of pressure balance.

[0030] Each wing element 20 has an air intake zone 23 and an exhaust zone 24 on its left and right sidewalls. The air intake zone 23 is located at the leading edge of the wing element 20, where the "leading edge" refers to the part near the opening of the wing element 20. The high-speed airflow will directly impact the air intake zone 23 of the wing element 20, thereby forming a high-pressure airflow with a strong shock wave in the air intake zone 23. The exhaust zone 24 is located at the bottom of the wing element 20. Each wing element 20 has an air intake hole 25 on its left and right sidewalls, which connects the air intake zone 23 and the pressure stabilizing chamber 21. The air intake hole 25 is inclined from the outside to the inside, from the direction close to the opening of the wing element 20 to the direction away from the opening of the wing element 20, so as to facilitate the high-pressure airflow of the strong shock wave in the air intake zone 23 to be drawn into the pressure stabilizing chamber 21. Each wing element 20 also has an exhaust hole 26 on its left and right sidewalls, which connects the exhaust zone 24 and the ventilation chamber 22. The exhaust hole 26 is inclined from the inside to the outside, from the direction close to the opening of the wing element 20 to the direction away from the opening of the wing element 20, so as to facilitate the airflow in the ventilation chamber 22 to be drawn into the external exhaust zone 24.

[0031] Optionally, there is a certain interval between the air intake zone 23 and the exhaust zone 24. Alternatively, the air intake port 25 is connected to the area of ​​the pressure stabilizing chamber 21 near the opening of the wing element 20, and the exhaust port 26 is connected to the area of ​​the ventilation chamber 22 near the bottom of the wing element 20, thus making the interval between the air intake port 25 and the exhaust port 26 relatively large. Alternatively, the exhaust port 26 is located after the shock wave foot of the strong shock wave formed in the air intake zone 23. Due to the sudden change in flow field pressure near the shock wave foot, local high pressure, airflow turbulence, and even the induction of shock wave oscillation are prone to occur. Therefore, by placing the exhaust port 26 after the shock wave foot, the exhaust from behind the shock wave foot can reduce the intensity of the strong shock wave formed in the air intake zone 23 through jet disturbance, weaken the mutual interference between the strong shock wave and the boundary layer on the outer sidewall of the wing element 20, avoid flow separation induced by the strong shock wave, and reduce wave drag. Alternatively, the exhaust port 26 is located in front of or within the separation zone where flow separation is expected to occur in the exhaust zone 24. When the airflow passes over the side wall of the wing element 20, if the adverse pressure gradient is too large, the boundary layer airflow on the outer side of the wing element 20 will detach from the side wall of the wing element 20, forming flow separation. A large number of vortices will be generated in the separation zone, resulting in a decrease in lift and a sharp increase in drag. Exhausting in front of or within the separation zone can inject energy into the boundary layer, delay or eliminate flow separation, expand the stable flight angle of attack range of the aircraft, and improve aerodynamic efficiency.

[0032] Optionally, the air intake holes 25 on the left / right sidewall of each wing element 20 are arranged in one or more rows, and the exhaust holes 26 on the left / right sidewall of each wing element 20 are arranged in one or more rows. Alternatively, the air intake holes 25 on the left / right sidewall of each wing element 20 are arranged in two rows, and the exhaust holes 26 on the left / right sidewall of each wing element 20 are arranged in two rows. Again, it is optional that both the air intake holes 25 and the exhaust holes 26 are through-holes at the micrometer or millimeter level. Alternatively, the air intake holes 25 are round holes to facilitate machining and reduce processing costs, and the exhaust holes 26 are slit-shaped holes, especially narrow slit-shaped holes, with the extension direction of the exhaust holes 26 being the same as the direction in which they are arranged in rows. Setting the exhaust holes 26 as slit-shaped holes, especially narrow slit-shaped holes, can make the exhaust more uniform and improve aerodynamic efficiency.

[0033] In this application, the sidewall of the wing element 20 is no longer a solid body, but has a cavity structure inside. When a high-speed airflow (transonic or supersonic) impacts the wing element 20, a high-pressure airflow with a strong shock wave is formed at the leading edge of the wing element 20. This high-pressure airflow at the leading edge of the wing element 20 is then "drawn" into the pressure-stabilizing cavity 21 inside the sidewall through the air intake holes 25 on the sidewall. This process weakens the intensity of the strong shock wave at the leading edge of the wing element 20, achieving a "pressure relief and wave reduction" effect. The airflow entering the pressure-stabilizing cavity 21 (with...) The higher total pressure then converges in the pressure stabilizing chamber 21 and the ventilation chamber 22, thereby stabilizing and homogenizing the airflow pressure. Then, the stable and homogenized airflow is "blown" back into the flow field outside the sidewall through the exhaust port 26 on the sidewall of the wing element 20. Since the exhaust port 26 is located in the boundary layer outside the sidewall of the wing element 20, the blown airflow injects energy into the boundary layer, thereby effectively resisting the adverse pressure gradient and inhibiting or delaying flow separation, playing the role of "blowing to prevent separation".

[0034] At high angle of attack, the air intake 25 on the side wall of the windward wing element 20 draws in a large amount of air, while the exhaust 26 on the side wall of the leeward wing element 20 actively discharges more airflow due to the internal and external pressure difference, thus forming a passive and asymmetrical "intake and blow" control, which can effectively suppress large-scale flow separation on the leeward side and thus expand the effective angle of attack range.

[0035] Based on the above, the leading edge of the outer frame 10 and / or the inner wing element 20 of the outer frame 10 can be designed with a swept-back shape to further reduce wave drag from a macroscopic perspective and achieve synergistic effect with the above-mentioned microscopic passive control structure.

[0036] The advantages of this application are: 1. Expanded operating speed range and improved transonic performance: By depressurizing at the leading edge of the wing element sidewall, the intensity of the shock wave can be effectively weakened, the peak drag in the transonic region can be significantly reduced, and the "blocking" phenomenon can be eliminated, so that the grid rudder can still maintain effective control in the transonic region, greatly improving the flight quality of the aircraft in the entire speed range.

[0037] 2. Expanded operating angle of attack range and enhanced maneuverability: By actively blowing air onto the leeward side to suppress flow separation, the stall angle of attack of the grid rudder can be significantly delayed, allowing it to maintain linear and predictable control characteristics over a wider angle of attack range, thereby improving the aircraft's high maneuverability and lateral maneuverability during return.

[0038] 3. Reduced flight drag and improved economy: Throughout the supersonic flight phase, continuous shock wave attenuation and separation control effectively reduced the wave drag and pressure drag of the grid fins, improving the overall lift-to-drag ratio of the aircraft. For reusable launch vehicles, this means higher recovery efficiency and lower fuel consumption.

[0039] 4. Enhanced structural and control reliability: The reduction in shock wave intensity and flow separation means that the unsteady pressure pulsation and chattering loads on the grid rudder surface are reduced, which is conducive to extending the structural life and improving the stability of the actuation system. At the same time, the high reliability of the passive control scheme itself also provides a guarantee for flight safety.

[0040] 5. Potential for weight reduction and cost reduction: Improved aerodynamic thermal environment may allow the use of lighter and lower-cost materials. In addition, advanced processes such as additive manufacturing (3D printing) can enable the integral molding of this complex structure, which is expected to optimize manufacturing costs while ensuring performance.

[0041] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0042] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A wide-operating-domain grid rudder with an integrated shock wave control structure, comprising: An outer frame and multiple wing elements located within the outer frame, characterized in that each wing element has a pressure-stabilizing cavity and a ventilation cavity communicating with the pressure-stabilizing cavity inside its sidewall, the pressure-stabilizing cavity being close to the opening of the wing element in which it is located, and the ventilation cavity being close to the bottom of the wing element in which it is located. Each wing element has an air intake area and an exhaust area on its left and right sidewalls. The air intake area is located at the leading edge of the wing element, and the exhaust area is located at the bottom of the wing element. Each wing element has an air intake hole on its left and right sidewalls that connects the air intake area and the pressure stabilizing chamber, and an exhaust hole on its left and right sidewalls that connects the exhaust area and the ventilation chamber.

2. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 1, characterized in that, The air intake vents gradually tilt from the outside to the inside, from the direction of the opening closest to the wing element to the direction of the opening furthest from the wing element, while the exhaust vents gradually tilt from the inside to the outside, from the direction of the opening closest to the wing element to the direction of the opening furthest from the wing element.

3. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 1 or 2, characterized in that, The width of the pressure stabilizing chamber is greater than the width of the venting chamber.

4. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 1 or 2, characterized in that, The pressure stabilizing chamber and ventilation chamber inside the sidewall of each wing element are either independent of or interconnected with the pressure stabilizing chamber and ventilation chamber inside the sidewall of adjacent wing elements.

5. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 4, characterized in that, The pressure stabilizing chamber and ventilation chamber inside the side wall of the wing element connected to the external frame are interconnected with the pressure stabilizing chamber and ventilation chamber inside the side wall of other wing elements through channels in the external frame.

6. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 1 or 2, characterized in that, There is a certain interval between the induced draft zone and the exhaust zone.

7. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 1 or 2, characterized in that, The exhaust port is located after the shock foot of the strong shock wave formed in the intake zone, and the exhaust port is located before or within the separation zone in which flow separation is expected to occur in the exhaust zone.

8. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 1 or 2, characterized in that, The air intake holes on the left / right sidewall of each wing element are arranged in one / multiple rows, and the exhaust holes on the left / right sidewall of each wing element are arranged in one / multiple rows.

9. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 1 or 2, characterized in that, Both the air intake vent and the exhaust vent are through pores at the micrometer or millimeter level.

10. The wide-operating-domain grid fin of the integrated shock wave control structure according to claim 1 or 2, characterized in that, The air intake hole is a round hole, and the exhaust hole is a slit-shaped hole, with the extension direction of the exhaust hole being the same as the direction in which the exhaust holes are arranged in a row.

Images