Rotary switch cooperatively regulated trailing edge blowing burst generator and method of use thereof

Abstract

The application relates to a rotary switch cooperatively regulated tail edge air blowing gust generator and a use method thereof, and belongs to the technical field of wind tunnel tests. The rotary switch cooperatively regulated tail edge air blowing gust generator comprises a wing profile shell assembly, a gas supply pipeline assembly, a rotary switch assembly and a control system. The tail edge of the wing profile shell is provided with a multi-nozzle array, the rotary switch is composed of independent detachable rotary shaft units, the air blowing flow variation law can be changed by adjusting the installation combination of the rotary shaft units corresponding to the nozzles, and various customized gust outputs with consistent or inconsistent main frequencies and consistent or inconsistent phases can be realized. The control system adopts a PID or model prediction control algorithm, the rotary shaft rotation angle is fed back through an encoder, the gas supply mass flow is monitored through a flowmeter, the rotary shaft rotating speed and the gas supply pressure are cooperatively adjusted in a closed loop, the amplitude drift and the frequency deviation problems of the gust field caused by the air source fluctuation and the flow field interference under open loop control are solved, and the stability and controllability of high-speed / high-frequency gusts are significantly enhanced. The application has no inertial load and compact structure, and can be adapted to various wind tunnels.

Description

Technical Field

[0001] This invention relates to a trailing edge blowing gust generator with a rotary switch that can be coordinated and controlled, and its usage method, belonging to the field of wind tunnel testing technology. Background Technology

[0002] To improve aerodynamic efficiency and reduce structural weight, modern large aircraft generally employ high-aspect-ratio wings with a high proportion of composite materials. This lightweight design significantly increases wing flexibility, making gust problems particularly prominent during transonic flight. Vertical gust loads can be the most severe flight load condition, thus necessitating research into gust load prediction and active gust mitigation control technologies during the aircraft design phase. A key foundation for this research lies in building a high-speed wind tunnel gust testing system capable of simulating real flight conditions.

[0003] Accurate prediction of gust loads is a necessary step in aircraft design, and wind tunnel testing is a crucial means of achieving this goal. The gust generator is a core component of the gust testing system. Currently, common oscillating blade gust generators are limited by their drive power, making it difficult to increase their oscillation frequency and amplitude under high wind speeds, thus primarily suitable for low-speed wind tunnels. Regarding high-speed gust generators, existing wind tunnel technologies utilize trailing edge blowing gust generators, which control the airflow through multiple sets of solenoid valves. However, these are relatively large and generally only suitable for large wind tunnels of 2 meters or more, lacking versatility for wind tunnels of different sizes.

[0004] Therefore, there is an urgent need to propose a trailing edge blowing gust generator with a rotary switch that can be coordinated and controlled, and its usage method, in order to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a trailing edge blowing gust generator with a rotary switch for coordinated control and a method of use. The rotary switch-controlled trailing edge blowing gust generator is vertically installed at the inlet section of a wind tunnel nozzle. Under the action of the gust generator, controllable and adjustable regular gust disturbances can be generated, thereby achieving the gust environment required in gust wind tunnel experiments. A brief overview of the invention is given below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention.

[0006] The technical solution of this invention:

[0007] Option 1: A trailing edge blowing gust generator with rotary switch controllable, comprising an airfoil housing assembly, an air supply pipeline assembly, a rotary switch assembly, and a control system. The airfoil housing assembly is formed by an upper airfoil plate, a lower airfoil plate, a left airfoil wall plate, and a right airfoil wall plate. The airfoil housing assembly has an interconnected front pressure stabilizing chamber and a rear adjustment chamber inside. The trailing edge of the airfoil housing assembly has a jet channel with a width of no more than 2 mm, and the trailing edge is provided with a multi-nozzle array structure.

[0008] The gas supply pipeline assembly includes a gas supply pipeline, on which a flow monitoring element and a pressure regulating valve are connected in series, and the gas supply pipeline is connected to the upper end plate of the airfoil.

[0009] The rotary switch assembly includes an upper drive source, a lower drive source, an upper adapter shaft encoder, a lower adapter shaft encoder, a front rotary shaft assembly, and a rear rotary shaft assembly.

[0010] The rear rotating shaft assembly passes through the rear adjustment cavity, and its two ends are respectively mounted to the upper end plate and the lower end plate of the airfoil via the upper end bearing and the lower end bearing of the rear rotating shaft; the front rotating shaft assembly passes through the rear adjustment cavity, and its two ends are respectively mounted to the upper end plate and the lower end plate of the airfoil via the upper end bearing and the lower end bearing of the front rotating shaft.

[0011] The output shaft of the upper drive source is connected to the upper drive source adapter shaft, and the upper drive source adapter shaft is connected to the rear rotating shaft assembly through the upper adapter shaft coupling; the output shaft of the lower drive source is connected to the lower drive source adapter shaft, and the lower drive source adapter shaft is connected to the front rotating shaft assembly through the lower adapter shaft coupling.

[0012] The upper adapter shaft encoder is mounted on the upper drive source adapter shaft, and the lower adapter shaft encoder is mounted on the lower drive source adapter shaft;

[0013] The front and rear rotating shaft assemblies have the same structure, each including a rotating shaft and several rotating shaft units. The cross-section of the middle part of the rotating shaft is a regular polygon. The rotating shaft units are independently and detachably installed on the rotating shaft. The number and position of the rotating shaft units correspond one-to-one with the array of nozzles on the trailing edge of the airfoil assembly.

[0014] The trailing edge of the airfoil housing assembly is provided with a trailing edge nozzle partition seal, which is installed on the left side panel of the airfoil.

[0015] The control system is electrically connected to the upper drive source, the lower drive source, the upper adapter shaft encoder, the lower adapter shaft encoder, the flow monitoring element, and the pressure regulating valve, respectively.

[0016] Preferably, the cross-section of the rotating shaft unit is elliptical, three-bladed, four-bladed, or circular.

[0017] Preferably, an airfoil seal is provided between the right airfoil panel and the left airfoil panel; an airfoil upper end plate seal is provided between the airfoil upper end plate and the right airfoil panel and the left airfoil panel; and an airfoil lower end plate seal is provided between the airfoil lower end plate and the right airfoil panel and the left airfoil panel.

[0018] Option 2, the method of using the trailing edge blowing gust generator that can be coordinated and controlled by a rotary switch, is based on the aforementioned trailing edge blowing gust generator and includes the following steps:

[0019] S1. Target setting: Input the target gust parameters, and the closed-loop control system calculates the target rotary switch motion law and the target air supply pressure;

[0020] S2. Real-time acquisition: The upper and lower adapter shaft encoders acquire the actual rotation angles of the rear and front rotating shaft assemblies, the flow monitoring element acquires the mass flow rate in the air supply pipeline, and the flow field sensor acquires the gust flow field parameters.

[0021] S3. Deviation Calculation: The closed-loop control system compares the target value with the actual value to calculate the rotary switch motion deviation and the gas supply pressure deviation.

[0022] S4. Coordinated adjustment: The upper and lower drive sources correct the rotation speed and angle / phase of the rear and front rotating shaft assemblies according to the motion deviation of the rotary switch, and the pressure regulating valve adjusts the air supply pressure of the air supply pipeline according to the pressure deviation.

[0023] Preferably, the rotation waveforms of the front rotating shaft assembly and the rear rotating shaft assembly are one or more combinations of sine wave, triangle wave, square wave, pulse wave or random gust, and the two can rotate at the same or different frequencies.

[0024] Preferably, the rotating shaft units in the front and rear rotating shaft assemblies are installed without phase difference in the radial direction, so that the rotating shaft assemblies have a straight cross section after assembly.

[0025] Preferably, in the front and rear rotating shaft assemblies, each rotating shaft unit is installed radially according to a phase difference, and there is a pre-installation offset angle between each rotating shaft unit.

[0026] Preferably, when one of the front rotating shaft assembly and the rear rotating shaft assembly is set to a constantly open state, the other is set to a periodically closed state.

[0027] Preferably, when the rotating shaft assembly rotates at a constant speed, the control system maintains a constant pressure in the pressure stabilizing chamber through the pressure regulating valve; when a variable frequency or variable amplitude gust is generated, the control system synchronously adjusts the rotation speed of the upper and lower drive sources and the air supply pressure of the pressure regulating valve.

[0028] Preferably, in the front and rear rotating shaft assemblies, when the rotating shaft unit adopts a circular cross section, the corresponding trailing edge array nozzles do not generate gust excitation.

[0029] The present invention has the following beneficial effects:

[0030] 1. This invention adopts pure mechanical rotary control, without electromagnetic hysteresis and high-frequency attenuation. Compared with the solenoid valve solution, it has no pulsation and no delay. By coupling the motion law of the rotary switch with the gas supply mass flow rate / gas supply pressure in a closed loop, the amplitude and frequency can be independently adjusted, the control error is extremely small, the response is in milliseconds, and the resistance to gas source pressure fluctuations and wind tunnel flow disturbances is strong.

[0031] 2. This invention replaces the solenoid valve assembly with a mechanical rotary switch, eliminating the need for complex pneumatic and electrical control structures. It has no inertial oscillating components, low power consumption, reliable sealing, and long service life. It supports proportional scaling design and can be adapted to various high-speed wind tunnels of all sizes, breaking through the limitations of traditional scaled-down applications.

[0032] 3. In this invention, the rotating shaft assembly adopts a modular array layout. The rotating shaft unit is independently detachable. By adjusting the installation and combination of the rotating shaft units at the corresponding positions of each nozzle, the variation law of the blowing flow of each nozzle can be changed, realizing different blowing forms of each nozzle, including gusts with consistent main frequency and phase; gusts with consistent main frequency but inconsistent phase; gusts with inconsistent main frequency; and gusts with inconsistent main frequency and phase. It can generate multiple types of gust excitations with different frequencies and phases, providing diverse experimental conditions for the study of dynamic response of complex gust fields of aircraft.

[0033] 4. This invention relies on multi-frequency coupling technology to reproduce real atmospheric multi-frequency superposition disturbances, which closely matches the actual flight and service environment of the aircraft; the test conditions can be accurately replicated and repeated, effectively improving the authenticity and confidence of wind tunnel test data;

[0034] 5. This invention can simultaneously excite multiple vibration modes of a structure, reproduce complex resonance responses, and easily expose extreme dangerous conditions and design defects; at the same time, it covers wide-frequency fatigue loads, significantly shortens the test cycle, and accurately verifies the structural life and the robustness of the flight control system. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the tail-edge blowing gust generator that can be coordinated and controlled by a rotary switch according to the present invention.

[0036] Figure 2 This is an exploded schematic diagram of the tail-edge blowing gust generator that can be coordinated and controlled by the rotary switch of the present invention.

[0037] Figure 3 This is a schematic diagram of the internal structure of the trailing edge blowing gust generator that can be coordinated and controlled by a rotary switch according to the present invention.

[0038] Figure 4 This is an assembly diagram of the rotary switch assembly in this invention.

[0039] Figure 5 This is an assembly diagram of the airfoil shell assembly in this invention.

[0040] Figure 6 This is a schematic diagram of the rotary switch assembly in this invention.

[0041] Figure 7 This is an exploded view of the rotating shaft assembly in this invention.

[0042] Figure 8 This is a cross-sectional view of the rotating shaft assembly in this invention.

[0043] Figure 9 This is a schematic diagram showing the cooperation between the front voltage stabilizing cavity and the rear adjustment cavity with the rotary switch assembly in this invention.

[0044] Figure 10 This is a schematic diagram of the Coanda effect in the trailing edge flow of the trailing edge blow gust generator that can be coordinated and controlled by the rotary switch of the present invention.

[0045] Figure 11 This is a schematic diagram of the jet intensity adjustment at the trailing edge channel in the trailing edge blowing gust generator that can be coordinated and controlled by the rotary switch of the present invention. (a) is a schematic diagram of the rotary switch assembly in the vertical position, (b) is a schematic diagram of the rotary switch assembly in the vertical position, and (c) is a schematic diagram of the rotary switch assembly in the vertical position.

[0046] Figure 12 This is a schematic diagram of the cross-sectional shape of the rotating shaft unit in the tail-edge blowing gust generator that can be coordinated and controlled by the rotary switch of the present invention. (a) is a schematic diagram when the cross-sectional shape of the rotating shaft unit is elliptical, (b) is a schematic diagram when the cross-sectional shape of the rotating shaft unit is three-bladed, and (c) is a schematic diagram when the cross-sectional shape of the rotating shaft unit is four-bladed.

[0047] Figure 13 This is a schematic diagram of the rotary shaft unit combination for different gust forms in the trailing edge blowing gust generator that can be coordinated and controlled by the rotary switch of the present invention. (a) is a schematic diagram of the rotary shaft unit combination when the frequency and phase of the gust are consistent, (b) is a schematic diagram of the rotary shaft unit combination when the frequency and phase of the gust are consistent, (c) is a schematic diagram of the rotary shaft unit combination when the frequency and phase of the gust are inconsistent, and (d) is a schematic diagram of the rotary shaft unit combination when the frequency and phase of the gust are inconsistent.

[0048] Figure 14This is a comparison of the calculation results of the influence of the width of the trailing edge jet channel of the airfoil shell component on the gust velocity in the trailing edge blowing gust generator that can be coordinated and controlled by the rotary switch of the present invention. Among them, (a) is a schematic diagram of the model with different blowing hole heights, and (b) is a time history curve of the gust velocity at the same position behind the blade.

[0049] Figure 15 This is a comparison chart of the calculation results of the influence of jet intensity on the velocity of the wind field in the trailing edge blowing gust generator that can be coordinated and controlled by the rotary switch of the present invention.

[0050] In the diagram: 1-Upper drive source, 2-Upper drive source adapter shaft, 3-Upper adapter shaft encoder, 4-Upper adapter shaft cover plate, 5-Upper adapter shaft cover plate seal, 6-Upper adapter shaft seal, 7-Upper adapter shaft coupling, 8-Airfoil upper end plate, 9-Airfoil upper end plate seal, 10-Front rotating shaft upper bearing, 11-Rear rotating shaft upper bearing, 12-Front rotating shaft assembly, 13-Rear rotating shaft assembly, 14-Front rotating shaft lower bearing, 15- 16-Lower end bearing of rear rotating shaft; 17-Airfoil lower end plate seal; 18-Lower transition shaft coupling; 19-Lower transition shaft seal; 20-Lower transition shaft cover plate seal; 21-Lower transition shaft cover plate; 22-Lower transition shaft encoder; 23-Lower drive source transition shaft; 24-Lower drive source; 25-Tail flange nozzle partition seal; 26-Left airfoil side panel; 27-Airfoil seal; 28-Right airfoil side panel; 29- 30 - Air inlet seal; 31 - Air supply pipe cover seal; 32 - Air supply pipe; 33 - Rotating shaft; 34 - First left half; 35 - Second left half; 36 - Third left half; 37 - Fourth left half; 38 - Fifth left half; 39 - Sixth left half; 40 - First right half; 41 - Second right half; 42 - Fourth right half; 43 - Fifth right half; 44 - Sixth right half; 45 - First rotating shaft. 46-Second rotating shaft upper seal, 47-Third rotating shaft upper seal, 48-Fourth rotating shaft upper seal, 49-Fifth rotating shaft upper seal, 50-Sixth rotating shaft upper seal, 51-First rotating shaft lower seal, 52-Second rotating shaft lower seal, 53-Third rotating shaft lower seal, 54-Fourth rotating shaft lower seal, 55-Fifth rotating shaft lower seal, 56-Sixth rotating shaft lower seal. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0052] The connections mentioned in this invention are divided into fixed connections and detachable connections. Fixed connections, also known as non-detachable connections, include but are not limited to conventional fixed connection methods such as folded connections, riveted connections, adhesive connections, and welded connections. Detachable connections include but are not limited to conventional disassembly methods such as threaded connections, snap-fit ​​connections, pin connections, and hinged connections. When a specific connection method is not explicitly defined, it is assumed that at least one existing connection method can always be found to achieve the function, and those skilled in the art can choose according to their needs. For example, a welded connection can be chosen for fixed connections, and a hinged connection can be chosen for detachable connections.

[0053] Example 1: Combination Figures 1-14 This embodiment describes a trailing edge blowing gust generator that can be coordinated and controlled by a rotary switch, including an airfoil housing assembly, an air supply pipeline assembly, a rotary switch assembly, and a control system.

[0054] The airfoil housing assembly is formed by an upper airfoil plate 8, a lower airfoil plate 17, a left airfoil panel 26, and a right airfoil panel 28. An upper airfoil plate seal 9 is provided between the upper airfoil plate 8 and the right airfoil panel 28 and the left airfoil panel 26; a lower airfoil plate seal 16 is provided between the lower airfoil plate 17 and the right airfoil panel 28 and the left airfoil panel 26; and an airfoil seal 27 is provided between the right airfoil panel 28 and the left airfoil panel 26. These seals include, but are not limited to, one or more of rubber gaskets and felt gaskets, used to ensure the airtightness of the airfoil housing assembly.

[0055] The airfoil housing assembly contains an interconnected front pressure-stabilizing chamber and a rear adjustment chamber, such as... Figure 9 The airfoil shell assembly has jet channels with a width of no more than 2 mm at its trailing edge, and a multi-nozzle array structure is provided at the trailing edge. For example... Figure 5 and Figure 6 As shown, a trailing edge nozzle partition seal 25 is provided at the trailing edge of the airfoil housing assembly. This trailing edge nozzle partition seal 25 is installed on the left side panel 26 of the airfoil, and its function is to ensure that the nozzles do not cross-ventilate each other. The trailing edge nozzle partition seal 25 includes, but is not limited to, one or more of rubber gaskets and felt gaskets, and its connection with the left side panel 26 of the airfoil is one of adhesive bonding, riveting, or threaded connection.

[0056] The air supply pipeline assembly includes an air supply pipeline 31, on which a flow monitoring element and a pressure regulating valve are connected in series. The air supply pipeline 31 is connected to the upper end plate 8 of the airfoil, and the mating point is sealed by an air inlet seal 29, which includes, but is not limited to, one or more of rubber gaskets and felt gaskets. The cover plate of the air supply pipeline 31 is sealed to the outer wall of the wind tunnel nozzle by an air supply pipeline cover plate seal 30, which includes, but is not limited to, a rubber sealing ring and a felt gasket.

[0057] Flow monitoring elements are used to measure the mass flow rate in pipelines in real time, including but not limited to one or more of differential pressure flow meters, vortex flow meters, and turbine flow meters. Pressure regulating valves adjust the pressure according to the action commands issued by the control system to achieve dynamic regulation of the gas supply flow, including but not limited to one or more of pneumatic pressure regulating valves, electric pressure regulating valves, and hydraulic pressure regulating valves.

[0058] The rotary switch assembly includes an upper drive source 1, a lower drive source 24, an upper adapter shaft encoder 3, a lower adapter shaft encoder 22, a front rotary shaft assembly 12, and a rear rotary shaft assembly 13. The upper drive source 1 and the lower drive source 24 include, but are not limited to, servo motors.

[0059] The rear rotating shaft assembly 13 extends through the rear adjustment cavity, and its two ends are respectively mounted to the upper airfoil plate 8 and the lower airfoil plate 17 via the upper rear rotating shaft bearing 11 and the lower rear rotating shaft bearing 15, respectively. The front rotating shaft assembly 12 extends through the rear adjustment cavity, and its two ends are respectively mounted to the upper airfoil plate 8 and the lower airfoil plate 17 via the upper front rotating shaft bearing 10 and the lower front rotating shaft bearing 14, respectively. The aforementioned bearings include, but are not limited to, one or more of deep groove ball bearings, tapered roller bearings, and thrust roller bearings.

[0060] The output shaft of the upper drive source 1 is connected to the upper drive source adapter shaft 2, and the upper drive source adapter shaft 2 is connected to the rear rotating shaft assembly 13 via the upper adapter shaft coupling 7. The output shaft of the lower drive source 24 is connected to the lower drive source adapter shaft 23, and the lower drive source adapter shaft 23 is connected to the front rotating shaft assembly 12 via the lower adapter shaft coupling 18. The upper drive source 1 and the upper drive source adapter shaft 2, and the lower drive source 24 and the lower drive source adapter shaft 23 are connected by keys, and the key connection type used includes, but is not limited to, a flat key connection and a spline connection.

[0061] The upper adapter shaft coupling 7 and the lower adapter shaft coupling 18 include, but are not limited to, rigid couplings with both ends connected by keys. That is, the upper drive source adapter shaft 2, the rear rotating shaft assembly 13 and the upper adapter shaft coupling 7, and the lower drive source adapter shaft 23, the front rotating shaft assembly 12 and the lower adapter shaft coupling 18 are all connected by keys. The key connection forms include, but are not limited to, a flat key connection and a spline connection.

[0062] The upper adapter shaft encoder 3 is mounted on the upper drive source adapter shaft 2, and the lower adapter shaft encoder 22 is mounted on the lower drive source adapter shaft 23. The upper adapter shaft encoder 3 and the lower adapter shaft encoder 22 are either absolute encoders or hybrid encoders, used to detect and provide feedback on information such as the rotation angle, current phase, and speed of the rotating shaft assembly in real time.

[0063] The upper adapter shaft cover plate 4 and the lower adapter shaft cover plate 21 are installed on the outside of the wind tunnel nozzle. The upper adapter shaft cover plate 4 is sealed to the outer wall of the wind tunnel nozzle by the upper adapter shaft cover plate seal 5, and the lower adapter shaft cover plate 21 is sealed to the outer wall of the wind tunnel nozzle by the lower adapter shaft cover plate seal 20. The upper adapter shaft cover plate 4 is sealed to the upper drive source adapter shaft 2 by the upper adapter shaft seal 6, and the lower adapter shaft cover plate 21 is sealed to the lower drive source adapter shaft 23 by the lower adapter shaft seal 19. The above-mentioned seals include, but are not limited to, one or more of rubber sealing rings and felt rings.

[0064] like Figure 7 and Figure 8 As shown, the front rotating shaft assembly 12 and the rear rotating shaft assembly 13 have identical structures, each including a rotating shaft 32 and several rotating shaft units. The cross-section of the middle part of the rotating shaft 32 is a regular polygon, such as a regular hexagon, so the minimum adjustable phase angle of the rotating shaft unit is 60°. The rotating shaft units are independently and detachably mounted on the rotating shaft 32, and the number and position of the rotating shaft units correspond one-to-one with the array of nozzles on the trailing edge of the airfoil assembly.

[0065] Each rotating shaft unit includes one of the following: a first left half 33, a second left half 34, a third left half 35, a fourth left half 36, a fifth left half 37, and a sixth left half 38; a corresponding one of the following: a first right half 39, a second right half 40, a third right half 41, a fourth right half 42, a fifth right half 43, and a sixth right half 44; and corresponding upper and lower seals. Specifically, each rotating shaft unit consists of four parts: a left half, a right half, an upper seal, and a lower seal. The left and right halves are locked together by screws; the upper seal is locked together with the left and right halves by screws; and the lower seal is also locked together with the left and right halves by screws. The left and right halves are positioned with the upper and lower seals by stop joints. In the axial direction, both ends of the rotating shaft 32 are positioned with the rotating shaft unit by stop joints.

[0066] The upper seals corresponding to each rotating shaft unit are, respectively, the first rotating shaft upper seal 45, the second rotating shaft upper seal 46, the third rotating shaft upper seal 47, the fourth rotating shaft upper seal 48, the fifth rotating shaft upper seal 49, and the sixth rotating shaft upper seal 50; the lower seals are, respectively, the first rotating shaft lower seal 51, the second rotating shaft lower seal 52, the third rotating shaft lower seal 53, the fourth rotating shaft lower seal 54, the fifth rotating shaft lower seal 55, and the sixth rotating shaft lower seal 56. These seals are used to ensure a good seal between the rotating shaft assembly and the inner wall of the airfoil housing adjustment cavity, preventing unintended air leakage, and include, but are not limited to, one or more of rubber gaskets and felt gaskets.

[0067] The cross-section of the rotating shaft unit is elliptical, three-bladed, four-bladed, or circular; see [reference]. Figure 12 The upper and lower seals are used to ensure a good seal between the rotating shaft assembly and the inner wall of the airfoil housing adjustment cavity, preventing unintended air leakage. The upper and lower seals include, but are not limited to, one or more of rubber gaskets and felt gaskets.

[0068] The control system is electrically connected to the upper drive source 1, the lower drive source 24, the upper adapter shaft encoder 3, the lower adapter shaft encoder 22, the flow monitoring element, and the pressure regulating valve. The control system incorporates a PID or model predictive control algorithm to achieve coupled closed-loop control of the rotary switch's motion law and the air supply pressure.

[0069] The assembly process of the gust generator in this embodiment is as follows: The upper bearing 10 of the front rotating shaft and the upper bearing 11 of the rear rotating shaft are installed on the upper airfoil plate 8 connected to the airfoil upper end plate seal 9; the lower bearing 14 of the front rotating shaft and the lower bearing 15 of the rear rotating shaft are installed on the lower airfoil plate 17 connected to the airfoil lower end plate seal 16; the two ends of the front rotating shaft assembly 12 are respectively fitted with the upper bearing 10 and the lower bearing 14 of the front rotating shaft, and the two ends of the rear rotating shaft assembly 13 are respectively fitted with the upper bearing 11 and the lower bearing 15 of the rear rotating shaft; the right airfoil wall panel 28 connected to the airfoil seal 27 is connected and fastened to the upper airfoil plate 8 and the lower airfoil plate 17 using fasteners; the left airfoil wall panel 26 connected to the trailing edge nozzle partition seal 25 is connected and fastened to the upper airfoil plate 8 and the lower airfoil plate 17 using fasteners, thus completing the assembly of the airfoil shell assembly.

[0070] The assembled airfoil shell assembly is vertically installed on the inlet section of the wind tunnel nozzle. The upper airfoil plate 8 and the lower airfoil plate 17 contact the inner wall of the wind tunnel nozzle and are connected by fasteners. Then, the upper adapter shaft coupling 7, which mates with the rear rotating shaft assembly 13, and the lower adapter shaft coupling 18, which mates with the front rotating shaft assembly 12, are installed. The upper adapter shaft cover plate 4, which is connected to the upper adapter shaft cover plate seal 5, and the lower adapter shaft cover plate 21, which is connected to the lower adapter shaft cover plate seal 20, are then installed on the outside of the wind tunnel nozzle. The upper drive source 1 and the lower drive source 24 are installed on the outside of the wind tunnel nozzle. The output shaft of the upper drive source 1 is connected in sequence to the upper drive source adapter shaft 2, the upper adapter shaft coupling 7, and the rear rotating shaft assembly 13. The output shaft of the lower drive source 24 is connected in sequence to the lower drive source adapter shaft 23, the lower adapter shaft coupling 18, and the front rotating shaft assembly 12. An upper drive source adapter shaft 3 and a lower drive source adapter shaft 22 are respectively installed on the upper drive source adapter shaft 2 and the lower drive source adapter shaft 23. The upper drive source adapter shaft 2 and the upper adapter shaft cover plate 4, and the lower drive source adapter shaft 23 and the lower adapter shaft cover plate 21 are sealed with an upper adapter shaft seal 6 and a lower adapter shaft seal 19, respectively. Finally, the air supply pipe 31 is installed on the outside of the wind tunnel nozzle. The air supply pipe 31 cover plate is sealed to the outer wall of the wind tunnel nozzle with an air supply pipe cover plate seal 30. The air supply pipe 31 is sealed at its mating point with the airfoil upper end plate 8 with an air inlet seal 29, completing the assembly.

[0071] The gust generator in this embodiment utilizes the Coanda effect of trailing edge flow to produce vertical gusts. Airflow originates from an external air source, flows through the air supply pipe 31 into the front pressure-stabilizing chamber of the airfoil assembly, then into the rear regulating chamber, and finally exits through the jet channel at the trailing edge of the airfoil assembly. When the jet approaches the wall, viscosity causes the fluid on the wall side to be carried away, creating a low-pressure zone. The pressure difference forces the jet towards the wall, generating a wall adhesion effect, thus forming a vertical gust.

[0072] The front rotating shaft assembly 12 and the rear rotating shaft assembly 13 act as rotary switches, adjusting the trailing edge jet intensity by regularly changing the degree of rotation. For example... Figure 11 As shown: When all rotating shaft components are in a vertical position, the jet intensity is almost zero, and no vertical velocity is generated, such as... Figure 11 In (a); when the rotating shaft assembly rotates to a certain angle, the jet intensity is small, resulting in a small vertical velocity, such as... Figure 11 (b) In this context, when all rotating shaft components are in a horizontal position, the jet intensity is at its maximum, generating a large vertical gust velocity, such as... Figure 11 (c) in the middle.

[0073] The jet intensity is determined by both the rotational speed of the rotating shaft assembly (which determines the jet flow area) and the air supply pressure. The gust frequency can be adjusted by controlling the rotational speed of the rotating shaft assembly, and the gust amplitude can be adjusted by controlling the air supply pressure.

[0074] like Figure 14 As shown, the effects of three jet channel widths (2mm, 3mm, and 5mm) on gust velocity were calculated. The results show that the smaller the jet channel width, the greater the gust velocity amplitude. Considering both machining processes and gust intensity requirements, the jet channel width should not exceed 2mm. Figure 15 As shown, the greater the jet intensity, the stronger the flow effect behind the trailing edge, and the greater the gust speed amplitude.

[0075] Example 2: Combination Figures 1-14 This embodiment describes the use of the rotary switch-controlled trailing edge blowing gust generator, based on the rotary switch-controlled trailing edge blowing gust generator of embodiment one. The method of using the rotary switch-controlled trailing edge blowing gust generator of this embodiment includes the following steps:

[0076] S1, Target Given:

[0077] Input the target gust parameters, namely frequency, amplitude, and waveform, and the closed-loop control system calculates the motion law of the target rotary switch and the target air supply pressure. The motion law of the rotary switch includes the time-varying curves of the rotational speed and rotation angle / phase of the front rotary shaft assembly 12 and the rear rotary shaft assembly 13.

[0078] S2, Real-time data acquisition:

[0079] The upper adapter shaft encoder 3 and the lower adapter shaft encoder 22 acquire the actual rotation angles of the rear rotating shaft assembly 13 and the front rotating shaft assembly 12; the flow monitoring element acquires the mass flow rate in the air supply pipeline 31; and the flow field sensor arranged in the wind tunnel test section acquires gust flow field parameters, including gust speed and frequency.

[0080] S3, Deviation Calculation:

[0081] The closed-loop control system compares the target value with the actual value and calculates the rotary switch motion deviation and the air supply pressure deviation. The rotary switch motion deviation includes the angle or phase deviation and the speed deviation.

[0082] S4, Coordinated Regulation:

[0083] The upper drive source 1 and lower drive source 24 correct the rotation speed, angle, or phase of the rear rotating shaft assembly 13 and the front rotating shaft assembly 12 in real time according to the motion deviation of the rotary switch, ensuring that the rotary switch moves according to the target law; the pressure regulating valve synchronously adjusts the air supply pressure of the air supply pipeline 31 according to the pressure deviation, realizing the coupling matching between the opening degree of the rotary switch and the air supply pressure. This coupled closed-loop control solves the problem of amplitude drift and frequency deviation caused by air source fluctuations and flow field interference in the gust field under open-loop control.

[0084] In this embodiment, the gust generator utilizes the Coanda effect of trailing edge flow, causing the jet to deviate from its original direction and adhere to the convex curved surface. According to the Coanda effect, given the jet density ρ, jet velocity V, and wall curvature radius R, a reverse pressure gradient will be generated perpendicular to the streamlines and along the direction pointing towards the center of curvature (centripetal).

[0085]

[0086] That is, the pressure decreases in the direction of the center of curvature (low pressure on the wall side) and increases in the direction away from the center of curvature. The greater the curvature (the smaller R), the lower the pressure on the wall side, the greater the pressure difference between the inside and outside, and the stronger the adsorption.

[0087] Where p is the hydrostatic pressure and n is the normal direction pointing to the center of curvature;

[0088] When the jet is stably attached to the wall, the pressure difference between the inside and outside of the jet provides the centripetal force (normal attachment force) Δp:

[0089]

[0090] Among them, C c Let be the Coanda adhesion coefficient, which is related to wall roughness, curvature, and Reynolds number. Given the jet boundary layer thickness δ and the jet width b, the adhesion force per unit width F´ is:

[0091]

[0092] Total normal adsorption force F:

[0093]

[0094] Where b is the jet width;

[0095] Determining wall adhesion / separation, i.e., the critical condition:

[0096] like If the jet remains attached to the wall, Jet separation, where the critical radius of curvature That is, if the radius of curvature R is too small and the jet velocity V is too high, the centrifugal force will be greater than the adhesion force, causing the adhesion to separate from the wall. Here, Δp max This represents the maximum permissible pressure difference.

[0097] The total energy of the jet in the gust generator will determine the gust velocity amplitude. The magnitude of the total jet energy is determined by the jet mass flow rate. The rotation angle / phase of the front rotating shaft assembly 12 and the rear rotating shaft assembly 13 determines the jet flow area. When the jet flow area, gas type, and temperature are constant, the gas supply pressure will directly determine the jet mass flow rate, and thus determine the total jet energy.

[0098] The control system calculates the jet flow area A based on the rotation angle / phase of the rotating shaft assembly. Given the gas flow velocity v in the gas supply pipeline, the fluid volumetric flow rate Q in the gust generator can be calculated. v :

[0099] Q v =A·v

[0100] The fluid mass flow rate Q m :

[0101] Q m =ρ·Q v

[0102] For compressible fluids, when the gas type and temperature are constant, the fluid density ρ and absolute pressure P have a one-to-one mapping relationship. Therefore, the fluid volumetric flow rate Q can be determined based on the motion law of the rotary switch. v Then, the fluid mass flow rate Q can be controlled by controlling the gas supply pressure. m .

[0103]

[0104] Where P is absolute pressure; R s is the specific gas constant, which depends only on the type of gas; T is the thermodynamic temperature.

[0105] By adjusting the installation and assembly of the rotating shaft units at the corresponding positions of each nozzle, the variation pattern of the airflow at each nozzle can be altered, achieving customized gust output. Specifically, this includes the following typical application methods:

[0106] (1) The trailing edge array nozzles generate gusts with consistent main frequency and phase: the rotating shaft units in the front rotating shaft assembly 12 and the rear rotating shaft assembly 13 are installed without phase difference in the radial direction, so that the rotating shaft assembly is a straight section after assembly. The rotation waveforms of the front rotating shaft assembly 12 and the rear rotating shaft assembly 13 are one or a combination of sine waves, triangular waves, rectangular waves, pulse waves or random gusts, and the two can rotate at the same or different frequencies. For example, if only a single-frequency gust is required, the two rotate at the same frequency and phase; if two different main frequencies of gusts are required, they can rotate at different frequencies respectively. In addition, any rotating shaft assembly can act as a waveform cutoff switch: for example, the front rotating shaft assembly 12 rotates at a constant speed to generate a sine wave gust, and the rear rotating shaft assembly 13 is initially set to a constant open state. When it is necessary to cut off part of the waveform, the rear rotating shaft assembly 13 is kept in a closed state (intermittent on and off) within the cutoff time window, thereby realizing partial waveform cutoff.

[0107] (2) The trailing edge array nozzle generates gusts with consistent main frequencies but inconsistent phases: The rotating shaft units in the front rotating shaft assembly 12 and the rear rotating shaft assembly 13 are installed radially with phase differences, and there is a pre-installation offset angle between the rotating shaft units. By changing the relative positions of the different rotating shaft units with the radial direction of the rotating shaft 32 during installation, the trailing edge array nozzle can generate airflow disturbances with a fixed phase difference. At this time, when the cross-sectional shape of each rotating shaft unit is the same and the rotation law is the same, the trailing edge array nozzle of the corresponding gust generator will generate gusts with consistent main frequencies but inconsistent phases.

[0108] (3) The trailing edge array nozzles generate gusts with inconsistent main frequencies: The front rotating shaft assembly 12 and the rear rotating shaft assembly 13 use rotating shaft units with different cross-sectional shapes. An elliptical rotating shaft unit generates two gust disturbances in one rotation cycle, a three-bladed unit generates three gust disturbances, a four-bladed unit generates four gust disturbances, and so on. By replacing the rotating shaft units with different cross-sectional shapes, the corresponding trailing edge array nozzles can generate gusts of different frequencies. In particular, when the rotating shaft unit adopts a circular cross-section, it blocks the regulating cavity, and the corresponding trailing edge array nozzles do not generate gust excitation.

[0109] (4) The trailing edge array nozzles generate gusts with inconsistent main frequencies and phases: Combining the features of (2) and (3) above, different rotating shaft unit cross-sectional geometries are used in the front rotating shaft assembly 12 and the rear rotating shaft assembly 13. At the same time, each rotating shaft unit is installed radially according to the required phase difference, so that each nozzle generates gusts with different frequencies and phases.

[0110] When the rotating shaft assembly rotates at a constant speed, the control system maintains a constant pressure in the pressure stabilizing chamber through the pressure regulating valve (dynamic compensation of the air supply pressure achieves amplitude stabilization), ensuring the stability of the fixed-frequency gust amplitude. When generating variable-frequency or variable-amplitude gusts, the control system synchronously adjusts the rotational speed of the upper drive source 1 and the lower drive source 24 and the air supply pressure of the pressure regulating valve, collects and corrects feedback signals in real time, and ensures that the intensity of the trailing jet is precisely matched with the opening of the rotary switch, generating a high-precision, high-stability controllable gust field in the test section, achieving overshoot-free and high-response tracking.

[0111] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not describe the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A tail-edge blowing gust generator with rotary switch controllable, characterized in that: It includes an airfoil housing assembly, an air supply pipeline assembly, a rotary switch assembly and a control system. The airfoil housing assembly is formed by an upper airfoil plate (8), a lower airfoil plate (17), a left airfoil wall plate (26) and a right airfoil wall plate (28). The airfoil housing assembly has a front pressure stabilizing chamber and a rear adjustment chamber that are interconnected. The trailing edge of the airfoil housing assembly has a jet channel with a width of no more than 2 mm and a multi-nozzle array structure at the trailing edge. The gas supply pipeline assembly includes a gas supply pipeline (31), on which a flow monitoring element and a pressure regulating valve are connected in series, and the gas supply pipeline (31) is connected to the upper end plate (8) of the airfoil. The rotary switch assembly includes an upper drive source (1), a lower drive source (24), an upper adapter shaft encoder (3), a lower adapter shaft encoder (22), a front rotary shaft assembly (12), and a rear rotary shaft assembly (13). The rear rotating shaft assembly (13) passes through the rear adjustment cavity, and its two ends are respectively mounted on the upper airfoil plate (8) and the lower airfoil plate (17) via the upper rear rotating shaft bearing (11) and the lower rear rotating shaft bearing (15); the front rotating shaft assembly (12) passes through the rear adjustment cavity, and its two ends are respectively mounted on the upper airfoil plate (8) and the lower airfoil plate (17) via the upper front rotating shaft bearing (10) and the lower front rotating shaft bearing (14). The output shaft of the upper drive source (1) is connected to the upper drive source adapter shaft (2), and the upper drive source adapter shaft (2) is connected to the rear rotating shaft assembly (13) through the upper adapter shaft coupling (7); the output shaft of the lower drive source (24) is connected to the lower drive source adapter shaft (23), and the lower drive source adapter shaft (23) is connected to the front rotating shaft assembly (12) through the lower adapter shaft coupling (18); The upper adapter shaft encoder (3) is mounted on the upper drive source adapter shaft (2), and the lower adapter shaft encoder (22) is mounted on the lower drive source adapter shaft (23). The front rotating shaft assembly (12) and the rear rotating shaft assembly (13) have the same structure, both including a rotating shaft (32) and several rotating shaft units. The cross-section of the middle part of the rotating shaft (32) is a regular polygon. The rotating shaft units are independently and detachably installed on the rotating shaft (32). The number and position of the rotating shaft units correspond one-to-one with the array nozzles on the trailing edge of the airfoil assembly. A trailing edge nozzle partition seal (25) is provided at the trailing edge of the airfoil assembly, and the trailing edge nozzle partition seal (25) is installed on the left side panel (26) of the airfoil; The control system is electrically connected to the upper drive source (1), the lower drive source (24), the upper adapter shaft encoder (3), the lower adapter shaft encoder (22), the flow monitoring element, and the pressure regulating valve, respectively.

2. The tail-edge blowing gust generator with rotary switch-controlled coordination according to claim 1, characterized in that: The cross-section of the rotating shaft unit is elliptical, three-bladed, four-bladed, or circular.

3. The tail-edge blowing gust generator with rotary switch-controlled coordination according to claim 2, characterized in that: An airfoil seal (27) is provided between the right airfoil wall panel (28) and the left airfoil wall panel (26); an airfoil upper end plate seal (9) is provided between the airfoil upper end plate (8) and the right airfoil wall panel (28) and the left airfoil wall panel (26); and an airfoil lower end plate seal (16) is provided between the airfoil lower end plate (17) and the right airfoil wall panel (28) and the left airfoil wall panel (26).

4. The method of using the rotary switch-controlled trailing edge blowing gust generator is based on the rotary switch-controlled trailing edge blowing gust generator described in claim 2 or 3, characterized in that, Includes the following steps: S1. Target setting: Input the target gust parameters, and the closed-loop control system calculates the target rotary switch motion law and the target air supply pressure; S2, Real-time acquisition: The upper adapter shaft encoder (3) and the lower adapter shaft encoder (22) acquire the actual rotation angles of the rear rotating shaft assembly (13) and the front rotating shaft assembly (12), the flow monitoring element acquires the mass flow rate in the air supply pipeline (31), and the flow field sensor acquires the gust flow field parameters. S3. Deviation Calculation: The closed-loop control system compares the target value with the actual value to calculate the rotary switch motion deviation and the gas supply pressure deviation. S4. Coordinated adjustment: The upper drive source (1) and the lower drive source (24) correct the rotation speed and rotation angle / phase of the rotary shaft assembly (13) and the front rotary shaft assembly (12) according to the motion deviation of the rotary switch. The pressure regulating valve adjusts the air supply pressure of the air supply pipeline (31) according to the pressure deviation.

5. The method of using the tail-edge blowing gust generator with rotary switch controllable according to claim 4, characterized in that: The rotation waveforms of the front rotating shaft assembly (12) and the rear rotating shaft assembly (13) are sine waves, triangular waves, rectangular waves, pulse waves or random gusts or combinations thereof, and the two can rotate at the same or different frequencies.

6. The method of using the tail-edge blowing gust generator with rotary switch controllable according to claim 4, characterized in that: The rotating shaft units in the front rotating shaft assembly (12) and the rear rotating shaft assembly (13) are installed without phase difference in the radial direction, so that the rotating shaft assembly has a straight cross section after assembly.

7. The method of using the tail-edge blowing gust generator with rotary switch controllable according to claim 4, characterized in that: In the front rotating shaft assembly (12) and the rear rotating shaft assembly (13), each rotating shaft unit is installed radially according to the phase difference, and there is a pre-installation offset between each rotating shaft unit.

8. The method of using the tail-edge blowing gust generator with rotary switch controllable according to claim 4, characterized in that: In the front rotating shaft assembly (12) and the rear rotating shaft assembly (13), one is set to a constantly open state and the other is set to a periodically closed state.

9. The method of using the tail-edge blowing gust generator with rotary switch controllable according to claim 4, characterized in that: When the rotating shaft assembly rotates at a constant speed, the control system maintains the pressure of the pressure stabilizing chamber constant through the pressure regulating valve; when a variable frequency or variable amplitude gust is generated, the control system synchronously adjusts the speed of the upper drive source (1) and the lower drive source (24) and the air supply pressure of the pressure regulating valve.

10. The method of using the tail-edge blowing gust generator with rotary switch controllable according to claim 4, characterized in that: In the front rotating shaft assembly (12) and the rear rotating shaft assembly (13), when the rotating shaft unit adopts a circular cross section, the corresponding trailing edge array nozzle does not generate gust excitation.

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