Hypersonic vehicle control method without rudder based on high-energy synthetic jet flow field control

Abstract

The present application relates to a kind of high supersonic aircraft control method based on high-energy synthetic jet flow field control without surface.The method comprises: high-energy synthetic jet unit is arranged on the surfaceless high supersonic aircraft, high-energy synthetic jet unit is two groups;Two groups of high-energy synthetic jet unit are symmetrically arranged in the windward surface trailing edge region of surfaceless high supersonic aircraft;Surfaceless control method includes: high-energy synthetic jet unit receives attitude control command, generates array high-energy synthetic jet;In windward surface, array high-energy synthetic jet acts on the flow of high supersonic aircraft, and interacts with flow, and large-scale vortex structure and shock system structure are generated, to regulate the power and aerodynamic moment of high supersonic aircraft, adjusts the flight attitude of high supersonic aircraft.

Description

Technical Field

[0001] This invention relates to the field of aircraft control technology, and in particular to a control method for hypersonic aircraft without control surfaces based on high-energy synthetic jet flow field control. Background Technology

[0002] A hypersonic vehicle is an aircraft capable of reaching or exceeding Mach 5 during flight. Attitude control in hypersonic vehicles primarily employs two methods: control surface control and reaction control systems. In control surface control, hypersonic vehicles adjust their physical structure by changing the angle of control surfaces, thereby inducing changes in the surrounding flow field and achieving precise attitude adjustments. This process mainly relies on the action of mechanical structures such as hinges, meaning that the adjustment of control surface positions typically takes anywhere from a fraction of a second to several seconds. However, this mechanical actuation method has significant drawbacks. For example, interference between control surfaces and gap effects can significantly disrupt the hinge torque, reducing control accuracy and efficiency. Furthermore, under hypersonic flight conditions, control surfaces face extreme aerodynamic and thermal challenges. This not only requires high thermal protection capabilities but also necessitates additional thermal protection structures, which undoubtedly adds extra weight and complexity to the lightweight design of the aircraft.

[0003] The reaction control system (RCS), on the other hand, directly applies force by arranging a series of small engines on the sides of the hypersonic vehicle to control its attitude. This direct force application allows the hypersonic vehicle to make more flexible attitude adjustments in space. However, the small engines used in this control system are relatively heavy and require a significant amount of space, which has a considerable impact on the overall performance of the hypersonic vehicle. Summary of the Invention

[0004] Therefore, it is necessary to provide a control method for hypersonic vehicles based on high-energy synthetic jet flow field control that can reduce weight and achieve control without control surfaces, in order to address the above-mentioned technical problems.

[0005] A control method for a hypersonic vehicle without control surfaces based on high-energy synthetic jet flow field control is characterized by arranging high-energy synthetic jet units on the controlless hypersonic vehicle, wherein the high-energy synthetic jet units are arranged in two sets; the two sets of high-energy synthetic jet units are symmetrically arranged in the trailing edge region of the windward side of the controlless hypersonic vehicle; the control method includes:

[0006] The high-energy synthetic jet unit receives attitude control commands and generates an array of high-energy synthetic jets.

[0007] On the windward side, the array-type high-energy synthetic jet acts on the incoming flow of the hypersonic vehicle and interacts with the incoming flow to generate large-scale vortex structures and shock wave structures, thereby regulating the dynamics and aerodynamic torque of the hypersonic vehicle and adjusting its flight attitude.

[0008] In one embodiment, it further includes:

[0009] By increasing the temperature of the array-type high-energy synthetic jet, the energy of the large-scale vortex structure and the shock system structure is enhanced, thereby improving the control of the dynamic and aerodynamic torque of the hypersonic vehicle.

[0010] In one embodiment, the high-energy synthetic jet unit includes two or more high-energy synthetic jet exciters;

[0011] Two or more of the aforementioned high-energy synthetic jet exciters are arranged in the trailing edge region of the windward surface of the rudderless hypersonic vehicle, and are arranged in a spanwise array along the trailing edge.

[0012] In one embodiment, vortex structures interact between adjacent high-energy synthetic jet exciters.

[0013] In one embodiment, the array of high-energy synthetic jets generated by the high-energy synthetic jet exciter acts perpendicularly on the incoming flow of the hypersonic vehicle.

[0014] In one embodiment, the rudderless hypersonic vehicle is further provided with a high-pressure gas source, a constant pressure device, and a flow valve connected in sequence; the constant pressure device and the flow valve are respectively connected to a processor, and the processor is connected to a sensor; the flow valve is connected to the high-energy synthetic jet unit.

[0015] After receiving attitude control commands, the rudderless hypersonic vehicle acquires flight environmental parameters through its sensors and sends these parameters to the processor. The processor processes the environmental parameters and controls the opening and closing of the flow valve, thereby controlling the high-energy synthetic jet unit to generate the array-type high-energy synthetic jet.

[0016] In one embodiment, the high-pressure gas source is high-pressure stored liquid air.

[0017] In one embodiment, the high-pressure gas source is gas obtained through the air intake or engine bleed air.

[0018] In one embodiment, the high-energy synthetic jet exciter is an plasma synthetic jet exciter or a self-sustaining synthetic jet exciter.

[0019] In one embodiment, the flow valve is a one-way valve.

[0020] The aforementioned control method for hypersonic vehicles based on high-energy synthetic jet flow field control involves arranging two sets of high-energy synthetic jet units on the controlless hypersonic vehicle. The two sets of high-energy synthetic jet units are symmetrically arranged in the trailing edge region of the windward side of the controlless hypersonic vehicle. The control method includes: the high-energy synthetic jet units receiving attitude control commands and generating an array of high-energy synthetic jets; on the windward side, the array of high-energy synthetic jets acts on the incoming flow of the hypersonic vehicle and interacts with the incoming flow to generate large-scale vortex structures and shock wave structures, thereby regulating the dynamics and aerodynamic torque of the hypersonic vehicle and adjusting its flight attitude.

[0021] This invention is applied to a controlless hypersonic vehicle, which eliminates the original mechanical control surfaces and instead sets a high-energy synthetic jet exciter in the trailing edge region of the windward side. Through the interaction between the high-energy synthetic jet and the hypersonic incoming flow, a large-scale vortex structure and shock wave system structure are induced, thereby regulating the dynamic and aerodynamic torque of the hypersonic vehicle and adjusting its flight attitude. This reduces the weight of the hypersonic vehicle while achieving controlless control. Attached Figure Description

[0022] 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 the structures shown in these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a control method for a hypersonic vehicle without control surfaces based on high-energy synthetic jet flow field control in one embodiment.

[0024] Figure 2 This is a schematic diagram of the shock wave structure generated by an array-type high-energy synthetic jet in one embodiment.

[0025] Figure 3 This is a schematic diagram of a large-scale vortex structure generated by an array-type high-energy synthetic jet in one embodiment.

[0026] Figure 4 This is a schematic diagram of the arrangement of the high-energy synthetic jet exciter in one embodiment;

[0027] Figure 5 This is a schematic diagram illustrating the flow field structure characteristics of a hypersonic vehicle under mechanical control in one embodiment; wherein... Figure 5(a) shows the surface pressure distribution of the aircraft and the Mach number cloud diagram on the XY plane when the mechanical control surfaces are not deflected. Figure 5 (b) shows the surface pressure distribution of the aircraft and the Mach number cloud map on the XY plane when the mechanical control surfaces are deflected by 5°;

[0028] Figure 6 This is a schematic diagram illustrating the flow field structure characteristics of a hypersonic vehicle under high-energy synthetic jet array control in one embodiment; wherein, Figure 6 (a) shows the pressure distribution and Mach number cloud map on the leeward side. Figure 6 (b) shows the pressure distribution and Mach number cloud map on the windward side.

[0029] Figure labeling: 1. High-pressure gas source; 2. Constant pressure device; 3. Flow valve; 4. High-energy synthetic jet exciter; 5. Processor; 6. Sensor; 7. Surface-free hypersonic vehicle.

[0030] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0033] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly and specifically defined.

[0034] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection, an electrical connection, a physical connection, or a wireless communication connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0035] Under normal flight conditions, synthetic jet technology has demonstrated its ability to replace control surfaces in the attitude control of low-speed aircraft. The high-speed jet generated by synthetic jet is faster than the incoming flow, so it can attach to the curved wall under the Kodane effect to generate a "virtual control surface". It can change the circulation of the wing surface and thus change the forces and moments of the aircraft, achieving control surface-free flight control.

[0036] However, under high-speed flight conditions, and even hypersonic flight conditions, the total pressure of the synthesized jet is much lower than that under hypersonic conditions due to the high total pressure of the incoming flow. This results in not only a less significant effect on the flow field altered by the jet, but also the potential for back pressure phenomena. Therefore, under hypersonic flight conditions, traditional technologies still rely on primitive mechanical control surfaces, making it difficult to achieve control surface-free operation.

[0037] Based on this, the present invention eliminates the original mechanical control surfaces on the basis of traditional hypersonic vehicles. Instead, high-energy synthetic jet units are symmetrically arranged in the trailing edge region of the windward side of the control-free hypersonic vehicle. The high-energy synthetic jet units generate an array of high-energy synthetic jets. The array of high-energy synthetic jets strongly interferes with the incoming flow. First, a detached bow-shaped shock wave is formed at the leading edge of the jet. Then, a separate shock wave is formed at the boundary between the shock wave and the boundary layer, and a large-scale vortex structure is generated. These strong interferences cause high-pressure areas to appear at the leading edge and sides of the jet, thereby changing the dynamic and aerodynamic torque of the hypersonic vehicle, thus changing the overall aerodynamic state of the vehicle, and ultimately achieving attitude control of the vehicle.

[0038] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0039] In one embodiment, such as Figure 1 As shown, a control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control is provided, including the following steps:

[0040] Step 202: Arrange high-energy synthetic jet units on the rudderless hypersonic vehicle. There are two sets of high-energy synthetic jet units. The two sets of high-energy synthetic jet units are symmetrically arranged in the trailing edge region of the windward surface of the rudderless hypersonic vehicle.

[0041] Specifically, firstly, a model of a controlless hypersonic vehicle is constructed. Then, the flow field distribution of the controlless hypersonic vehicle is determined through simulation calculation. Based on the obtained flow field distribution, considering the control effect on the shock system and vortex structure, a high-energy synthetic jet unit is arranged near the trailing edge region of the windward side of the controlless hypersonic vehicle to achieve optimal control of the shock system and vortex structure.

[0042] During the simulation verification, the incoming flow condition was set as a pressure far field, the surface of the controlless hypersonic vehicle was set as an adiabatic non-slip wall, the jet was set as a pressure inlet, and the spatial flow field was solved based on the three-dimensional viscous compressible Navier-Stokes equations. At the same time, in order to ensure the accuracy of the numerical model simulation, the turbulence model was selected as the SST k-ω model, and the spatial discretization method adopted was the second-order upwind scheme.

[0043] Step 204: The high-energy synthetic jet unit receives attitude control commands and generates an array of high-energy synthetic jets.

[0044] Step 206: On the windward side, the array-type high-energy synthetic jet acts on the incoming flow of the hypersonic vehicle and interacts with the incoming flow to generate large-scale vortex structure and shock wave system structure, thereby regulating the dynamics and aerodynamic torque of the hypersonic vehicle and adjusting the flight attitude of the hypersonic vehicle.

[0045] High-energy synthetic jet propulsion is a highly flexible active flow control method. It involves injecting energy into a semi-enclosed cavity to create a jet. This jet interacts with the flow field, generating a torque on the aircraft. Changing the injected energy can create jets of varying strengths to suit different application scenarios, effectively mimicking traditional mechanical control surfaces to control the aircraft. Because the jet velocity is extremely high, flow field changes can occur in milliseconds, enabling more precise attitude adjustments and directional changes, thus improving flight control accuracy and maneuverability.

[0046] Specifically, in the high-energy synthetic jet unit, the arrayed arrangement of multiple high-energy synthetic jet exciters causes mutual interference in the flow field changes brought about by the multiple jets, thereby enhancing the generated large-scale vortex structure and shock system structure. More specifically, the arrayed high-energy synthetic jet generated by the arrayed high-energy synthetic jet exciters has a large area acting on the incoming flow, forming a larger high-pressure zone, making it difficult for the incoming flow to bypass the jet region. This results in strong interaction between the incoming flow and the jet. (See [reference needed]). Figure 2 As shown, it will form a distinct bow-shaped shock wave upstream of the jet, which in turn forms a more compact shock wave structure.

[0047] On the other hand, see Figure 3The high-energy synthetic jet generated by the array arrangement will form a flipping vortex pair downstream. The vortex has a wider circumferential influence on the downstream shock wave, resulting in a wider circumferential distribution of the low-pressure area of ​​the cone skirt. This reduces the pressure coefficient on the surface of the cone skirt, which can effectively improve the aerodynamic layout of the hypersonic vehicle, significantly reduce the vehicle's drag, increase lift, and enhance the stability and controllability of the vehicle when adjusting its flight attitude.

[0048] The aforementioned control method for hypersonic vehicles based on high-energy synthetic jet flow field control involves arranging two sets of high-energy synthetic jet units on the controlless hypersonic vehicle. The two sets of high-energy synthetic jet units are symmetrically arranged in the trailing edge region of the windward side of the controlless hypersonic vehicle. The control method includes: the high-energy synthetic jet units receiving attitude control commands and generating an array of high-energy synthetic jets; on the windward side, the array of high-energy synthetic jets acts on the incoming flow of the hypersonic vehicle and interacts with the incoming flow to generate large-scale vortex structures and shock wave structures, thereby regulating the dynamics and aerodynamic torque of the hypersonic vehicle and adjusting its flight attitude.

[0049] This invention is applied to a controlless hypersonic vehicle, which eliminates the original mechanical control surfaces and instead sets a high-energy synthetic jet exciter in the trailing edge region of the windward side. Through the interaction between the high-energy synthetic jet and the hypersonic incoming flow, a large-scale vortex structure and shock wave system structure are induced, thereby regulating the dynamic and aerodynamic torque of the hypersonic vehicle to adjust the flight attitude of the hypersonic vehicle. This reduces the weight of the hypersonic vehicle while achieving controlless control of the vehicle.

[0050] In one embodiment, the energy of large-scale vortex structures and shock systems is enhanced by increasing the temperature of the array-type high-energy synthetic jet, thereby improving the control of the dynamic and aerodynamic torque of the hypersonic vehicle.

[0051] It is understandable that, since the jet outlet is a sonic jet, changes in temperature will cause changes in jet velocity, density, etc., which in turn will cause changes in shock waves and recirculation zones.

[0052] Specifically, temperature control is introduced in this embodiment. Increasing the jet temperature enhances the control of the transverse jet. As the jet temperature increases, the exit velocity of the jet also increases accordingly, making the jet's obstruction effect more significant and leading to an increase in the area of ​​the high-pressure zone induced by the jet. Simultaneously, the vortex pairs induced by the jet have a larger vortex volume. With the increase in vortex volume, the interference effect of the vortex pairs on the shock wave becomes stronger. This enhancement effect makes the pressure reduction at the skirt more pronounced, thereby enhancing the pitching moment to some extent. This enhanced moment helps improve the missile's maneuverability.

[0053] More specifically, as the jet temperature increases, the volume of the horseshoe-shaped backflow region in front of the jet gradually increases, while the area of ​​the high-pressure region also expands. This is because the underexpanded jet expands and accelerates at the exit, resulting in strong mixing with the mainstream. Behind the jet, the velocity of the sonic jet increases accordingly, leading to a stronger interaction with the mainstream, a larger velocity gradient, and a corresponding increase in vorticity. Furthermore, as the temperature rises, the vortex structures developed from the Mach disk gradually increase in size, disappear at a faster rate, and shorten in length. The convergence velocity between different vortex structures accelerates, causing the vortex pairs generated by the Mach disk to decrease in vorticity at a faster rate, ultimately forming a unified vortex pair that develops backward. This backward-developing vortex pair affects the downstream shock wave intensity, causing further changes in the pressure distribution at the skirt position, making the pressure reduction at the skirt more significant, thereby enhancing the control of the hypersonic vehicle's dynamic and aerodynamic torque.

[0054] In one embodiment, the high-energy synthetic jet unit includes two or more high-energy synthetic jet actuators; the two or more high-energy synthetic jet actuators are arranged in the trailing edge region of the windward surface of the rudderless hypersonic vehicle and are arranged in a spanwise array along the trailing edge.

[0055] It is understandable that high-energy synthetic jet exciters possess advantages such as no air source, simple structure, and light weight. Based on this, the controlless hypersonic vehicle of this embodiment adopts a high-energy synthetic jet exciter. This lightweight design can achieve better performance in acceleration, climb, and maneuverability. Furthermore, when combined with an array of jets, it exhibits more significant, sensitive, and precise attitude adjustments and directional changes, enabling the hypersonic vehicle to execute more complex commands, thereby improving mission adaptability and success rate, and breaking through the performance limitations of traditional hypersonic vehicles. On the other hand, it allows the vehicle to consume less fuel to reach the required speed and altitude, which means that the fuel load can be reduced or the payload increased, thereby improving overall fuel efficiency. Moreover, with the same weight of fuel, the range can be extended, allowing for the execution of more missions.

[0056] On the other hand, low-speed aircraft are primarily affected by the aerodynamic laws of subsonic flow. When performing controlless operation, they typically place a dual-jet exciter at the trailing edge of the wing, i.e., the Coanda trailing edge. Hypersonic aircraft, however, are generally designed as wingless structures to minimize shock wave drag and aerodynamic heating. Therefore, the principle behind their high-energy synthetic jet exciter placement differs.

[0057] Specifically, see Figure 4The diagram shows the arrangement of the high-energy synthetic jet exciter in this invention. The flow field distribution of the rudderless hypersonic vehicle 7 is obtained through simulation calculation. Considering that it has the best control effect on the shock wave system and vortex structure, the high-energy synthetic jet exciter 4 is arranged near the trailing edge region of the windward side of the rudderless hypersonic vehicle 7. The lift coefficient, drag coefficient and pitch moment coefficient in this region are the smallest, and the control of the rudderless hypersonic vehicle 7 is more precise and sensitive.

[0058] Regarding the number of actuators, to form an array-type high-energy synthetic jet, it is best to use two or more high-energy synthetic jet actuators 4. These two or more actuators 4 are arranged in a spanwise array along the trailing edge. The array arrangement includes a single-row array arrangement, so that the vortex structures generated by adjacent jets can interact, and the width of the spanwise vortex is close to the width of the lifting surface, thereby maximizing the area of ​​the high-pressure zone on the windward side, and thus enabling more precise and sensitive control. Furthermore, the array arrangement also includes a multi-row array arrangement, with multiple rows of high-energy synthetic jet actuators 4 arranged at intervals to form a larger high-pressure area. When multiple rows are used, the arrangement can be a matrix array, a cross array, or a curved surface array, depending on the specific situation.

[0059] In one embodiment, vortex structures interact between adjacent high-energy synthetic jet exciters.

[0060] It is understandable that the high-energy synthetic jet exciter 4 is arranged in a spanwise array along the trailing edge, and the spanwise spacing is determined by the large-scale vortex structure generated by the two adjacent high-energy synthetic jets in the array. The spacing must satisfy the requirement that the two vortex structures can interact.

[0061] In one embodiment, an array of high-energy synthetic jets generated by a high-energy synthetic jet exciter acts perpendicularly on the incoming flow of the hypersonic vehicle.

[0062] It is understandable that when the angle between the jet and the free flow direction is obtuse (i.e., the jet blows upstream), using a high-energy synthetic jet array will increase the drag experienced by the hypersonic vehicle; when the angle is acute (i.e., the jet blows downstream), the high-energy synthetic jet array has insufficient control over the flow field, resulting in poor lift gain for the hypersonic vehicle and reduced control capability for the hypersonic vehicle without control surfaces. Therefore, the high-energy synthetic jet of this invention acts perpendicularly to the incoming flow of the hypersonic vehicle to maximize drag reduction and control capability without control surfaces.

[0063] In one embodiment, the rudderless hypersonic vehicle is also equipped with a high-pressure gas source 1, a constant pressure device 2, and a flow valve 3 connected in sequence; the constant pressure device 2 and the flow valve 3 are respectively connected to a processor 5, and the processor 5 is connected to a sensor 6; the flow valve 3 is connected to a high-energy synthetic jet unit.

[0064] After receiving attitude control commands, the rudderless hypersonic vehicle 7 uses sensor 6 to acquire flight environmental parameters and sends them to processor 5. After processing the environmental parameters, processor 5 controls the opening and closing state of flow valve 3, thereby controlling the high-energy synthetic jet unit to generate an array of high-energy synthetic jets.

[0065] In one embodiment, the high-pressure gas source 1 is high-pressure stored liquid air.

[0066] It is understandable that as the mass of the stored liquid gas gradually decreases, the gas pressure delivered by the high-pressure gas source 1 will change. The gas is first delivered to the constant pressure device 2 to ensure the constant output gas pressure, and then the flow rate of the output gas is stabilized by the flow valve 3 and delivered to the high-energy synthetic jet exciter 4.

[0067] During operation, when the rudderless hypersonic vehicle 7 requires large-angle adjustments and its altitude is above 20km, the flow valve 3 opens to ensure the high-energy synthetic jet exciter 4 can maintain its intake recovery and jet intensity within its operating cycle. When the rudderless hypersonic vehicle 7 is below 10km or its attitude adjustment angle is small, the flow valve 3 closes. In this case, the high-energy synthetic jet exciter 4 can achieve self-sustaining operation by drawing air from the wall during the intake recovery phase, saving air resources and reducing consumption. Under both operating conditions, the high-energy synthetic jet exciter 4 can generate a sufficiently strong jet to strongly interfere with the hypersonic incoming flow. The bow-shaped shock wave region and flow separation region formed in front of the jet create a significant high-pressure region on the wall of the rudderless hypersonic vehicle 7. The sum of this high-pressure region and the reaction force of the jet changes the force and torque of the vehicle, thereby adjusting its attitude.

[0068] In one embodiment, the flow valve is a check valve.

[0069] It is understandable that setting the flow valve 3 as a one-way valve can prevent back pressure from entering the fluid pipeline when the gas expands, thereby avoiding back pressure on the gas supply system.

[0070] In one embodiment, the high-pressure gas source is gas obtained through the intake manifold or engine bleed gas.

[0071] It is understandable that the air intake and engine themselves generate heat, especially the engine's exhaust gas temperature, which can reach over 3000K. By utilizing the gas from these locations, on the one hand, effective thermal management of the air intake and engine can be achieved, increasing the structural lifespan. On the other hand, jet temperature control can be considered during jet control, thereby further optimizing and enhancing the control of the dynamic and aerodynamic torques of hypersonic vehicles, improving the accuracy of flight control, and providing a new direction for the control of future hypersonic vehicles.

[0072] In one embodiment, the high-energy synthetic jet exciter is a plasma synthetic jet exciter or a self-sustaining synthetic jet exciter.

[0073] In one embodiment, the hypersonic vehicle control method without control surfaces based on high-energy synthetic jet flow field control of the present invention is compared with a reaction control system.

[0074] First, a jet interference factor is introduced to compare the differences in control mechanisms between the two methods. The jet interference factor K is used. f and K m This represents the ratio of the aerodynamic force / torque generated by the jet interference flow field to the thrust / torque generated by the jet itself. It is defined as:

[0075]

[0076]

[0077] Where F on F off and F j These are the aerodynamic forces when the jet opens, the aerodynamic forces when the jet closes, and the thrust generated by the jet itself, respectively. M on M off and M j These are the aerodynamic torque when the jet is open, the aerodynamic torque when the jet is closed, and the torque generated by the jet itself. A jet interference factor of 1 indicates that the additional aerodynamic force / torque generated in the controlled operation compared to the uncontrolled operation is entirely generated by the thrust / torque of the jet itself; a value greater than 1 indicates that the aerodynamic force / torque generated by the jet interference flow field is greater than the thrust / torque of the jet itself, i.e., the jet interference flow field generates additional aerodynamic force / torque; and a value less than 1 indicates that the jet interference flow field weakens the thrust / torque of the jet. The jet interference factor can also be called the jet amplification factor or the jet gain factor. Experiments have shown that when the high-energy synthetic jet array in this invention is open, the jet interference factor reaches 5 or higher. This indicates that the surfaceless control effect using high-energy synthetic jets mainly comes from the vortex structure generated by the jet and the interference effect of the jet on the shock wave system, rather than the thrust effect generated by the jet alone. This is the biggest difference from RCS control technology.

[0078] On the other hand, a comparison is made between mechanical control surface control and the control surfaceless control of the present invention.

[0079] See Figure 5 This is a schematic diagram illustrating the flow field structure characteristics of a hypersonic vehicle under mechanical control. Figure 5(a) shows the surface pressure distribution of the aircraft and the Mach number cloud diagram in the XY plane when the mechanical control surfaces are not deflected. At this time, the lift-drag coefficient and pitch moment coefficient of the aircraft are -0.36560, 0.25597 and -0.20220, respectively. Figure 5 (b) shows the surface pressure distribution and Mach number cloud diagram of the aircraft in the XY plane when the mechanical control surface is deflected by 5°. It can be seen that after the mechanical control surface is deflected, the area of ​​the low-pressure zone on the upper surface of the aircraft control surface increases, which increases the pressure difference between the upper and lower surfaces of the aircraft, and increases the lift and pitch moment coefficients of the aircraft. The control surface deflection causes the windward side to generate oblique shock waves, which increases the shock wave drag of the aircraft. At this time, the lift drag coefficient and pitch moment coefficient of the aircraft are -0.34260, 0.25855 and -0.15278, respectively.

[0080] See Figure 6 This is a schematic diagram illustrating the flow field structure characteristics of a hypersonic vehicle under high-energy synthetic jet array control. Figure 6 (a) shows the pressure distribution and Mach number contour plot on the leeward side. Figure 5 (a) Similar when the mechanical control surface does not deflect; Figure 6 (b) shows the pressure distribution and Mach number cloud map on the windward side. It can be seen that under the influence of the large-scale vortex structure and shock wave system of the high-energy synthetic jet, the pressure distribution on the leeward side of the aircraft and the flow field around the aircraft have changed dramatically. The high-pressure area near the jet outlet and downstream has increased significantly. At this time, the lift coefficient, drag coefficient and pitch moment coefficient are -0.31789, 0.25536 and -0.15791, respectively.

[0081] In summary, the hypersonic vehicle control method without control surfaces based on high-energy synthetic jet flow field control proposed in this invention achieves the same control effect of high-energy synthetic jet in the pitch direction as that of mechanical control surfaces with a 5° deflection, and achieves the goal of increasing lift and reducing drag.

[0082] It is understandable that in hypersonic environments, a separation zone appears at the leading edge of the lateral jet. Due to the interaction between the separated shock wave and the bow shock wave, a local high-pressure zone is formed around the jet exit on the windward side. Compared with mechanical control surfaces, the pressure on the windward side is significantly higher, and the area of ​​the high-pressure zone is significantly larger. The leeward side is a low-pressure zone, and its pressure distribution is similar to that under mechanical control surfaces. The change in the local pressure distribution on the windward side alters the torque experienced by the aircraft, thereby achieving attitude adjustment. The gain of the lateral jet mainly comes from the change in the flow field around the jet and the reaction force of the jet itself. Compared with the oblique shock wave drag generated by the deflection of mechanical control surfaces, the shock wave system generated by the high-energy synthetic jet can reduce wave drag, thereby reducing the drag experienced by the hypersonic aircraft. By controlling the high-energy synthetic jet arrays on both sides of the aircraft's lifting surface, the rolling torque generated by the differential action of the original mechanical control surfaces can be achieved.

[0083] Therefore, by arranging a high-energy synthetic jet exciter at the trailing edge of the windward side of a hypersonic vehicle, the surrounding flow field can be controlled, thereby achieving or even surpassing the attitude control effect of mechanical control surface deflection on the hypersonic vehicle.

[0084] It should be understood that, although Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0085] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0086] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control, characterized in that, High-energy synthetic jet units are arranged on a rudderless hypersonic vehicle, and there are two sets of high-energy synthetic jet units. The two sets of high-energy synthetic jet units are symmetrically arranged in the trailing edge region of the windward surface of the rudderless hypersonic vehicle. Each high-energy synthetic jet unit includes two or more high-energy synthetic jet exciters arranged in a spanwise array along the trailing edge. The rudderless hypersonic vehicle is also equipped with a high-pressure gas source, a constant pressure device, and a flow valve connected in sequence; the constant pressure device and the flow valve are respectively connected to a processor, and the processor is connected to a sensor; the flow valve is connected to the high-energy synthetic jet unit. The rudderless control method includes: The high-energy synthetic jet unit receives attitude control commands and generates an array of high-energy synthetic jets. On the windward side, the array-type high-energy synthetic jet acts on the incoming flow of the hypersonic vehicle and interacts with the incoming flow to generate large-scale vortex structures and shock wave structures, thereby regulating the dynamics and aerodynamic torque of the hypersonic vehicle and adjusting the flight attitude of the hypersonic vehicle. During operation, when the rudderless hypersonic vehicle needs to make large-angle adjustments and the vehicle altitude is above 20km, the flow valve opens to ensure that the high-energy synthetic jet exciter can absorb air and recover and maintain the intensity of the jet within its working cycle. When the flight altitude is below 10km or the attitude adjustment angle is small, the flow valve is closed, and the high-energy synthetic jet exciter is controlled to achieve self-sustaining operation by only drawing air from the wall during the air intake recovery phase.

2. The control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control according to claim 1, characterized in that, Also includes: By increasing the temperature of the array-type high-energy synthetic jet, the energy of the large-scale vortex structure and the shock system structure is enhanced, thereby improving the control of the dynamic and aerodynamic torque of the hypersonic vehicle.

3. The control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control according to claim 1 or 2, characterized in that, The interaction of vortex structures generated between adjacent high-energy synthetic jet exciters.

4. The control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control according to claim 3, characterized in that, The array of high-energy synthetic jets generated by the high-energy synthetic jet exciter acts perpendicularly on the incoming flow of the hypersonic vehicle.

5. The control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control according to claim 1 or 2, characterized in that, The high-pressure gas source is liquid air stored at high pressure.

6. The control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control according to claim 5, characterized in that, The high-pressure gas source is gas obtained through the air intake or engine bleed.

7. The control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control according to claim 1 or 2, characterized in that, The high-energy synthetic jet exciter is a plasma synthetic jet exciter or a self-sustaining synthetic jet exciter.

8. The control method for hypersonic vehicles without control surfaces based on high-energy synthetic jet flow field control according to claim 1 or 2, characterized in that, The flow valve is a one-way valve.

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