A circulation-controlled airfoil with adaptive step height

Abstract

The present invention discloses a circulation control wing with adaptive step height, wherein the main cross-section airfoil of the circulation control wing is a supercritical airfoil, and a circulation control device is arranged at the trailing edge of the main wing. By slidingly connecting the Coanda profile with the main wing, and using a set of drive control system to control their relative positions, the Coanda profile can realize precise movement between the first and second nozzles during the jet operation, and finally realize adaptive adjustment of the step height behind the nozzle according to the working pressure ratio of the jet air cavity, significantly expanding the effective working range of the circulation control device, and the jet is in the best attachment state within its effective working pressure ratio range, thereby improving the circulation control efficiency. In addition, the change of the step height will not cause changes in the appearance of other circulation control devices such as the Coanda camber, thereby improving the stability of the circulation control device and reducing the design difficulty.

Description

Technical Field

[0001] The invention belongs to the field of active flow control of aircraft, and in particular relates to a circulation control airfoil with an adaptive step height. Background Art

[0002] For traditional fixed-wing aircraft, the flight control system relies on various control surfaces, such as ailerons, flaps, spoilers, etc. These traditional control surfaces increase lift and control by forcibly changing the state of the incoming flow, forming a complex mechanical system.

[0003] Circulation control is an active flow control technology developed based on the Coanda effect. It controls the circulation around the airfoil to change the lift and aerodynamic moment to achieve the effect of lift control. A tangential jet is generated through the slit channel at the trailing edge of the airfoil, and the jet is mixed with the external flow and flows along the Coanda surface at the trailing edge, which greatly increases the circulation around the airfoil and thus increases the lift of the airfoil. At the same time, the Coanda jet at the trailing edge of the wing can also be used to form a virtual control surface to control the flight attitude. Compared with traditional mechanical control surfaces, the trailing edge of the circulation-controlled airfoil is blunter, with fewer moving parts, which reduces the number of parts, helping to reduce the weight of the system and improve the reliability and maintainability of the wing structure. In terms of military aircraft, it can effectively enhance stealth performance and improve maneuverability.

[0004] The circulation control device changes the momentum coefficient of the jet by changing the total pressure of the jet, thereby adjusting the jet's ability to adhere to the Coanda surface at the trailing edge. When the aircraft flies at transonic speed, it is difficult to achieve effective control of the subsonic jet. In order for the Coanda jet to effectively adhere to the trailing edge surface and obtain sufficient circulation control performance, the jet speed needs to reach supersonic speed. By adopting a convergence-divergence nozzle or setting a step behind the nozzle, the jet expansion can be effectively promoted, the jet reaches supersonic speed at the exit, the interaction between the shock wave and the boundary layer is weakened, and the critical separation pressure ratio of the jet is increased.

[0005] In actual engineering applications, due to the small size of the circulation control device and the difficulty of processing the contraction-expansion nozzle, in order to achieve the same circulation control effect, the method of setting a step behind the nozzle is often used. Patent CN111532419A discloses a circulation control unit for improving the adhesion pressure ratio of supersonic Coanda jets. By introducing a backward step of the nozzle, the expansion of the jet is promoted, and the adhesion pressure ratio of the supersonic Coanda jet of the jet is significantly increased. However, the height of the step is fixed, which enhances the circulation control performance under high pressure ratio conditions while weakening the circulation control performance under low pressure ratio conditions. In addition, in the design of conventional fixed steps, due to the symmetry of the upper and lower nozzle devices and the thickness constraint of the trailing edge of the airfoil, the height design range of the step is relatively small. At the same time, due to the different sizes of the expansion reflow zones required for jets with different pressure ratios, the fixed step height limits the effective pressure ratio range and lift efficiency of the circulation control device, thereby limiting the control performance of the aircraft. Summary of the invention

[0006] In view of the problem that the effective working pressure ratio range is small due to the fixed step height in the existing circulation control device, the present invention proposes a circulation control wing with adaptive step height, which can realize adaptive change of the step height behind the nozzle by slidingly connecting the Coanda surface with the airfoil body, thereby expanding the effective working pressure ratio range and enhancing the circulation control efficiency under various pressure ratio conditions within the range.

[0007] The technical solution of the present invention is:

[0008] The circulation control wing with adaptive step height, the cross-sectional airfoil of the wing body is a supercritical airfoil, and the circulation control device is arranged at the trailing edge of the wing body;

[0009] The circulation control device comprises two sets of jet units, a movable Coanda profile and a driving mechanism;

[0010] The first jet unit includes a first jet air cavity and a first nozzle; the second jet unit includes a second jet air cavity and a second nozzle; the first nozzle and the second nozzle are respectively located on the upper and lower surfaces of the airfoil; the first jet air cavity is connected to the first nozzle, and the second jet air cavity is connected to the second nozzle; high-pressure gas is generated by the first jet air cavity and ejected from the first nozzle; high-pressure gas is generated by the second jet air cavity and ejected from the second nozzle;

[0011] A Coanda surface is arranged between the first nozzle and the second nozzle; the Coanda surface is slidably connected to the wing body, and the Coanda surface can be driven to slide toward the first nozzle or the second nozzle by a driving mechanism; when the Coanda surface is in an intermediate position between the first nozzle and the second nozzle, a first step is formed between the first nozzle and the Coanda surface, and a second step is formed between the second nozzle and the Coanda surface; when the driving mechanism drives the Coanda surface to slide toward the first nozzle or the second nozzle, the height change of the first step or the second step can be adjusted.

[0012] The basic principle of this scheme is that the jet is generated by the air cavity, ejected through the nozzle, and flows along the Coanda surface due to the Coanda effect, thereby deflecting the direction of the jet, increasing the circulation around the airfoil, and thus increasing the lift of the airfoil. In addition, a step is set between the nozzle and the Coanda arc surface to promote jet expansion, weaken the intensity of the jet shock wave-boundary layer interaction, and avoid jet separation. At the same time, the relative position of the Coanda surface and the wing body is adjusted by the hydraulic system to achieve the change of the step height, which can control the attachment effect of Coanda jets with different pressure ratios, improve the critical separation pressure ratio of the jet, and the circulation control efficiency under various working pressure ratios.

[0013] Furthermore, the driving mechanism adopts a hydraulic driving mechanism, including a first hydraulic chamber and a second hydraulic chamber; during operation, the displacement data of the Coanda surface can be monitored according to the change of the liquid flow in the first hydraulic chamber or the second hydraulic chamber.

[0014] Furthermore, the first nozzle is composed of a first nozzle outer wall and a wing body; the second nozzle is composed of a second nozzle outer wall and a wing body; the chord length of the airfoil body is C, the trailing edge thickness is 1.2%C, the thickness of the first nozzle outer wall and the second nozzle outer wall is 0.05%C, and the opening height of the first nozzle and the second nozzle is 0.025%C.

[0015] Furthermore, the Coanda profile surface is selected as an arc surface, and the radius of the arc surface is 0.5%C. The step height varies in the range of 0 to 0.05%C.

[0016] Furthermore, the first jet unit and the second jet unit are symmetrically placed up and down on the trailing edge of the wing body.

[0017] Furthermore, lightening holes are arranged inside the Coanda profile along the span direction to reduce the weight of the circulation control device.

[0018] Furthermore, according to the total jet pressure and the jet static pressure of the first nozzle or the second nozzle, the Coanda surface is driven to move, so as to realize adaptive adjustment of the step height and enhance the attachment effect of the jet on the Coanda surface.

[0019] Furthermore, the method for realizing the adaptive adjustment of step height is:

[0020] When the heights of the first nozzle and the second nozzle are given, through numerical simulation, firstly, under a certain working pressure ratio, different first step heights are set to obtain the first step height value with the best circulation control effect under a specific pressure ratio; secondly, a series of working pressure ratio values ​​are set, and the above process is repeated to obtain the best first step height value for different working pressure ratios; finally, the working pressure ratio is fitted with the best height value; in actual application, the working pressure ratio value is obtained in real time, and the best first step height value is obtained according to the fitting data, and then the driving mechanism is controlled to realize the adaptive change of the step height.

[0021] Furthermore, the first jet air cavity and the second jet air cavity contain high-pressure gas, and the total pressure of the gas can be adjusted.

[0022] Further, the first nozzle and the second nozzle are only convergence nozzles or convergence-divergence nozzles.

[0023] Beneficial Effects

[0024] The present invention discloses a circulation control wing with adaptive step height, wherein the main cross-section airfoil of the circulation control wing is a supercritical airfoil, and a circulation control device is arranged at the trailing edge of the main wing. By slidingly connecting the Coanda profile with the main wing, and using a set of drive control system to control their relative positions, the Coanda profile can realize precise movement between the first and second nozzles during the jet operation, and finally realize adaptive adjustment of the step height behind the nozzle according to the working pressure ratio of the jet air cavity, significantly expanding the effective working range of the circulation control device, and the jet is in the best attachment state within its effective working pressure ratio range, thereby improving the circulation control efficiency. In addition, the change of the step height will not cause changes in the appearance of other circulation control devices such as the Coanda camber, thereby improving the stability of the circulation control device and reducing the design difficulty.

[0025] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 It is a schematic diagram of the cross-sectional structure of the adaptive step height circulation control wing of the present invention;

[0028] Figure 2 It is a structural schematic diagram of the circulation control device of the present invention;

[0029] Figure 3 It is an enlarged structural schematic diagram of the first nozzle area of ​​the circulation control device of the present invention;

[0030] Figure 4 It is a structural schematic diagram of the Coanda profile of the present invention;

[0031] Figure 5 It is a schematic diagram of the relative position of the Coanda profile and the wing body of the present invention;

[0032] Figure 6 This is a flow field diagram of a non-step jet when the Coanda jet pressure ratio of the present invention is 7;

[0033] Figure 7 This is a step jet flow field diagram when the Coanda jet pressure ratio of the present invention is 7;

[0034] Figure 8 It is a curve diagram of the lift increment ratio changing with the jet momentum coefficient under the working conditions without or with steps of the present invention.

[0035] Reference numerals:

[0036] 1. Wing body, 2. Circulation control device, 3. First jet air cavity, 4. First hydraulic cavity, 5. First nozzle area, 6. Coanda surface, 7. Second nozzle area, 8. Second hydraulic cavity, 9. Second jet air cavity, 10. First nozzle outer wall, 11. First nozzle, 12. First step, 13. Coanda camber, 14. Lightening hole, 15. Jet separation zone, 16. Downstream recirculation zone, 17. Jet expansion zone. DETAILED DESCRIPTION

[0037] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0038] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0039] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0040] The present invention provides a circulation control wing with adaptive step height, such as Figures 1 to 5 As shown, it includes a wing body 1 and a circulation control device 2. The cross-sectional airfoil of the wing body 1 of the circulation control wing is a supercritical airfoil, and the circulation control device 2 is arranged at the trailing edge of the wing body 1, and the circulation control device 2 can generate force and moment for controlling the flight of the aircraft.

[0041] like Figure 2 As shown, the circulation control device 2 includes two sets of jet units, a movable Coanda profile and a driving mechanism consisting of two hydraulic chambers. The two sets of jet units include a first jet air chamber 4, a first nozzle area 5, a second jet air chamber 9, and a second nozzle area 7. The two jet air chambers and the two nozzle areas are symmetrically arranged relative to the upper and lower surfaces of the airfoil.

[0042] according to Figure 3 The schematic diagram of the structure of the first nozzle area 5 is shown, and the first nozzle 11 is composed of the first nozzle upper wall 10 and the wing body 1 below. The first nozzle 11 and the Coanda arc surface 13 on the Coanda profile 6 form a first step 12. It is easy to understand that the second nozzle area 7 is symmetrically the same as the first nozzle area 5, and no further description is given here.

[0043] Coanda profile 6 structure Figure 4 As shown. It includes Coanda cambered surface 13 and lightening holes 14. Lightening holes are arranged inside the Coanda profile along the span direction to reduce the weight of the circulation control device. Between the Coanda profile 6 and the wing body 1 is a hydraulic drive system, which includes a first hydraulic chamber 4 and a second hydraulic chamber 8, to achieve fine displacement control of the Coanda profile. During the working process, its flow enters and exits synchronously and in equal amounts.

[0044] The first jet air cavity 3 and the second jet air cavity 9 are filled with high-pressure gas, and the total pressure of the gas can be adjusted. The gas source is preferably, but not limited to, an aircraft engine. The first nozzle 11 and the second nozzle are directly connected to the first jet air cavity 3 and the second jet air cavity 9, respectively. The high-pressure gas inside the first jet air cavity 3 or the second jet air cavity 9 is accelerated and ejected through the first nozzle 11 or the second nozzle. Further, the first nozzle 11 and the second nozzle can be only contraction nozzles or contraction-expansion nozzles. The jet is expanded and accelerated at the first step 12 or the second step and a reflow zone is formed to promote the attachment of the jet to the Coanda camber 13.

[0045] Under the joint action of the first hydraulic chamber 4 and the second hydraulic chamber 8, the Coanda profile 6 can be finely moved between the first nozzle 11 and the second nozzle. According to the change of the liquid flow in the first hydraulic chamber 4 or the second hydraulic chamber 8, the specific displacement data of the Coanda profile 6 can be monitored. Furthermore, according to the total pressure of the jet and the static pressure of the jet of the first nozzle 11 or the second nozzle, the height of the first step 12 or the second step can be adaptively adjusted to enhance the adhesion effect of the jet on the Coanda curved surface 13. Figure 5 As shown in the relative position of the Coanda surface and the wing body, the upper limit of the movement of the Coanda surface 6 is that the height of the first step 12 is equal to 0, and the lower limit of the movement is that the height of the second step is equal to 0, so as to avoid affecting the normal working switching of the first jet air cavity 3 and the second jet air cavity 9.

[0046] The Coanda arc surface is preferably but not limited to a circular arc, and can be changed according to design requirements. Similarly, the shape of the lightening hole is not unique, and its shape can be changed according to design requirements. In addition, other equipment can be installed therein. In this specific embodiment, it is regarded as a lightening hole structure for reducing the weight of the circulation control device, but it is not limited to this single function.

[0047] Through the hydraulic system, the first hydraulic chamber and the second hydraulic chamber are operated synchronously to push the Coanda surface to move between the first nozzle and the second nozzle, thereby changing the relative step height between the Coanda surface and the first nozzle or the second nozzle. Taking the first jet air chamber working and the second jet air chamber closed as an example, when the working pressure is relatively low, the expansion area required for the jet outlet is small, and the step is too high, which will lead to a large reflow area, which is not conducive to the attachment of the jet. At this time, the second hydraulic chamber works to push the Coanda surface to move toward the first nozzle, reduce the step height at the first nozzle, thereby reducing the reflow area behind the step and enhancing the attachment ability of the jet; when the working pressure ratio is too high and the jet is about to leave the Coanda arc surface, the expansion area required for the jet outlet is large. At this time, the first hydraulic chamber is used to push the Coanda surface to move toward the second nozzle, increase the step height at the first nozzle, promote jet expansion, reduce the interference intensity of the shock wave boundary layer between the jet and the wall, and enhance the jet attachment ability, thereby improving the performance of the circulation control device under high pressure ratio conditions. Through the above working process, the effective working pressure ratio range of the circulation control device can be significantly increased, thereby improving the efficiency of the circulation control device.

[0048] Here, we use NPR to represent the nozzle operating pressure ratio:

[0049]

[0050] Where P0 is the total pressure at the jet inlet, P ∞is the outlet ambient pressure. As the jet working pressure ratio gradually increases, the jet adhesion effect on the Coanda surface gradually weakens. When the jet is close to completely separating from the Coanda surface, the jet working pressure ratio is the critical separation pressure ratio.

[0051] Use momentum coefficient C μ Characterizing the jet intensity:

[0052]

[0053] in, is the mass flow rate at the jet outlet, V j is the jet velocity at the nozzle, q is the incoming flow pressure, and S is the reference area. For a specific nozzle shape and free flow parameters, the jet momentum coefficient increases with the increase of the working pressure ratio.

[0054] Use the lift increment ratio as the evaluation criterion for the efficiency of the circulation control device:

[0055]

[0056] Among them, C L is the lift coefficient.

[0057] In order to verify the above characteristics of the circulation control device with adaptive step height, this embodiment performs numerical simulation analysis on the circulation control device. Taking the first jet air cavity 3 working and the second jet air cavity 9 closed as an example, the working conditions of the circulation control device 2 with two different step heights are specifically compared. Figures 6 to 8 shown.

[0058] In this embodiment, the cross-sectional airfoil of the wing body 1 is preferably an OAT15A supercritical airfoil. The airfoil chord length is 230 mm, the trailing edge thickness is 2.76 mm, the upper wall thickness of the first nozzle is 0.115 mm, the height of the first nozzle 11 and the second nozzle is 0.0575 mm, and the Coanda profile is preferably an arc with a radius of 1.15 mm. The free flow Mach number is 0.73, and the Reynolds number is 3×10 6 , the airfoil angle of attack is 2.5°, and the total temperature of the jet is 300K. The SA turbulence model is selected in the numerical simulation method, and the implicit solution method and the Roe-FDS second-order upwind scheme are used to calculate the two-dimensional steady compressible NS equations. The jet working pressure ratio gradually increases from 2 until the jet is completely separated.

[0059] Figure 6 , Figure 7 In the flow field shown, the jet pressure ratio is 7 and the momentum coefficient is 0.00347. Figure 6It can be seen that under this pressure ratio condition, when the height of the first step 12 is 0, a larger jet separation area 15 is formed behind the first nozzle 11, and the separation position of the downstream jet is forward, forming a larger downstream reflow area 16 with the free flow passing through the lower surface of the airfoil. The circulation control efficiency is low, and the lift increment ratio is 52.099. In order to improve the circulation control efficiency under this pressure ratio condition, the Coanda surface 6 can be pushed downward by the first hydraulic chamber 4 to increase the height of the first step 12. In this embodiment, the height of the first step 12 is preferably 0.0575 mm. Its jet flow field is as follows Figure 7 As shown. Due to the presence of the step, the jet is effectively expanded after passing through the first nozzle 11, forming a larger jet expansion area 17, improving the jet adhesion ability, and the downstream reflow area 16 is also significantly reduced. The lift increment ratio is 59.571, which improves the circulation control efficiency.

[0060] like Figure 8 As shown in the figure, by comparing the circulation control efficiency of the above two conditions without steps and with steps, it can be concluded that when the jet momentum coefficient is less than 0.0019, that is, the working pressure ratio is less than 4, the circulation control efficiency of the condition without steps is higher; when the jet momentum coefficient is greater than 0.0019, that is, the working pressure ratio is greater than 4, the circulation control efficiency of the condition with steps is higher. In addition, when the jet momentum coefficient is greater than 0.0047, that is, the working pressure ratio is greater than 9.5, the circulation control efficiency of the condition without steps is less than 0, at which time the jet is completely separated, and the critical separation pressure ratio is 9.5. However, the condition with steps still has a positive circulation control efficiency when the momentum coefficient is greater than 0.0047, until the momentum coefficient is equal to 0.0059, that is, the working pressure ratio is equal to 12, the jet is completely separated, and the circulation control effect disappears, at which time the critical separation pressure ratio is 12. Therefore, when the circulation control efficiency is 0, the condition with steps has a higher momentum coefficient and a higher critical separation pressure ratio. Therefore, under different working pressure ratios, the height of the first step 12 can be adjusted by the coordinated work of the first hydraulic chamber 4 and the second hydraulic chamber 8, so that the circulation control efficiency can be optimized.

[0061] Furthermore, when the heights of the first nozzle 11 and the second nozzle are given, numerical simulation can be used to first set different heights of the first step 12 under a certain working pressure ratio to obtain the height value of the first step 12 with the best circulation control effect under a specific pressure ratio; secondly, a series of working pressure ratio values ​​are set, and the first step is repeated to obtain the best height value of the first step 12 with different working pressure ratios; finally, the working pressure ratio is fitted with the best height value, and the data is written into the automatic control system. In practical applications, the automatic control system obtains the working pressure ratio value in real time, outputs the best height value of the first step 12 through the existing fitting curve and inputs it into the hydraulic control system, automatically controls the first hydraulic chamber 4 and the second hydraulic chamber 8, and thus realizes the adaptive change of the step height.

[0062] Through the above specific implementation methods, the circulation control wing with adaptive step height proposed by the present invention realizes adaptive adjustment of the step height behind the nozzle by arranging a circulation control device at the trailing edge of the supercritical airfoil and arranging a hydraulic system between the Coanda surface and the wing body, thereby enhancing the adhesion ability of the jet under different working pressure ratio conditions and improving the control efficiency of the circulation control wing.

[0063] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A circulation-controlled wing with adaptive step height, characterized in that: The cross-sectional airfoil of the wing body is a supercritical airfoil, and a circulation control device is arranged at the trailing edge of the wing body; The circulation control device comprises two sets of jet units, a movable Coanda profile and a driving mechanism; The first jet unit includes a first jet air cavity and a first nozzle; the second jet unit includes a second jet air cavity and a second nozzle; the first nozzle and the second nozzle are respectively located on the upper and lower surfaces of the airfoil; the first jet air cavity is connected to the first nozzle, and the second jet air cavity is connected to the second nozzle; high-pressure gas is generated by the first jet air cavity and ejected from the first nozzle; high-pressure gas is generated by the second jet air cavity and ejected from the second nozzle; A Coanda surface is arranged between the first nozzle and the second nozzle; the Coanda surface is slidably connected to the wing body, and the Coanda surface can be driven to slide toward the first nozzle or the second nozzle by a driving mechanism; when the Coanda surface is in an intermediate position between the first nozzle and the second nozzle, a first step is formed between the first nozzle and the Coanda surface, and a second step is formed between the second nozzle and the Coanda surface; when the driving mechanism drives the Coanda surface to slide toward the first nozzle or the second nozzle, the height change of the first step or the second step can be adjusted.

2. The circulation-controlled wing with adaptive step height according to claim 1, characterized in that: The driving mechanism adopts a hydraulic driving mechanism, including a first hydraulic chamber and a second hydraulic chamber; during operation, the displacement data of the Coanda surface can be monitored according to the change of the liquid flow in the first hydraulic chamber or the second hydraulic chamber.

3. The circulation-controlled wing with adaptive step height according to claim 1, characterized in that: The first nozzle is composed of the first nozzle outer wall and the wing body; the second nozzle is composed of the second nozzle outer wall and the wing body; the chord length of the airfoil body is C, the trailing edge thickness is 1.2%C, the thickness of the first nozzle outer wall and the second nozzle outer wall is 0.05%C, and the opening height of the first nozzle and the second nozzle is 0.025%C.

4. The circulation-controlled wing with adaptive step height according to claim 1, characterized in that: The Coanda profile surface is selected as an arc surface, and the radius of the arc surface is 0.5%C; the step height variation range is 0 to 0.05%C.

5. The circulation-controlled wing with adaptive step height according to claim 1, characterized in that: The first jet unit and the second jet unit are symmetrically placed up and down at the trailing edge portion of the wing body.

6. The circulation-controlled wing with adaptive step height according to claim 1, characterized in that: Lightening holes are arranged inside the Coanda profile along the span direction to reduce the weight of the circulation control device.

7. The circulation-controlled wing with adaptive step height according to claim 1, characterized in that: According to the total jet pressure and the jet static pressure of the first nozzle or the second nozzle, the Coanda surface is driven to move, so as to realize adaptive adjustment of the step height and enhance the attachment effect of the jet on the Coanda surface.

8. The circulation-controlled wing with adaptive step height according to claim 7, characterized in that: The method to achieve adaptive adjustment of step height is: When the heights of the first nozzle and the second nozzle are given, through numerical simulation, firstly, under a certain working pressure ratio, different first step heights are set to obtain the first step height value with the best circulation control effect under a specific pressure ratio; secondly, a series of working pressure ratio values ​​are set, and the above process is repeated to obtain the best first step height value for different working pressure ratios; finally, the working pressure ratio is fitted with the best height value; in actual application, the working pressure ratio value is obtained in real time, and the best first step height value is obtained according to the fitting data, and then the driving mechanism is controlled to realize the adaptive change of the step height.

9. The circulation-controlled wing with adaptive step height according to claim 1, characterized in that: The first jet air cavity and the second jet air cavity contain high-pressure gas, and the total pressure of the gas can be adjusted.

10. The circulation-controlled wing with adaptive step height according to claim 1, characterized in that: The first and second nozzles are either convergence-only nozzles or convergence-divergence nozzles.

Images