A rotor tip vortex and dynamic stall vortex collaborative control device and method

Abstract

The present application belongs to the field of rotor control, and particularly relates to a rotor tip vortex and dynamic stall vortex cooperative control device and method. The cooperative control device comprises a self-sustaining synthetic jet exciter and a pressurized synthetic jet exciter; further comprising a pressurized channel arranged in the rotor and connected with the self-sustaining jet channel and the pressurized jet inlet, a control valve I arranged in the pressurized channel; a control valve II arranged on the self-sustaining jet inlet, and a one-way valve arranged in the pressurized jet inlet. The present application integrates two sets of synthetic jet exciters of self-sustaining and pressurized types, and utilizes the internally connected pressurized channel and valve system to realize the cooperative and adjustable control of the rotor tip vortex and dynamic stall vortex, and effectively improves the aerodynamic performance, suppresses the noise and vibration without external air source.

Description

Technical Field

[0001] This invention belongs to the field of rotor control, specifically relating to a rotor tip vortex and dynamic stall vortex coordinated control device and method. Background Technology

[0002] As the global low-altitude economy enters a phase of rapid development, emerging scenarios such as urban air traffic, emergency rescue, and logistics drones are placing higher demands on the performance of vertical takeoff and landing (VTOL) rotorcraft. Low-altitude aircraft need to operate efficiently, with low noise and high maneuverability in complex urban environments. However, traditional rotorcraft are constrained by two aerodynamic bottlenecks: rotor tip vortex interference and dynamic stall of the rotor's retreating blades. Their noise and speed limits severely restrict the large-scale development and application of low-altitude resources.

[0003] For low-altitude rotorcraft such as helicopters, the superposition of rotor blade rotational motion and forward speed during high-speed forward flight leads to severe airflow asymmetry. Specifically, the advancing blade has a higher relative velocity to the incoming flow, while the retreating blade has a lower velocity, resulting in periodic changes in the rotor blade angle of attack. The retreating blade typically operates at low speed and high angle of attack, making it prone to flow separation and complex dynamic stall phenomena. The dynamic stall vortex generated during this process can suppress separation and increase wing lift during the wing's pitch-up phase; however, its shedding during the pitch-down phase leads to a sharp deterioration of the aerodynamic environment, increasing energy consumption and reducing flight efficiency. Simultaneously, it can also induce vibration and noise, affecting aircraft stability and, in extreme cases, potentially causing complete loss of flight capability. The rotor blades rotating in the air generate spiral wake vortices. When these vortices (especially tip vortices) approach and interact with the trailing blade, they produce strong pressure fluctuations and cause blade vibration, resulting in rotor tip vortex interference. Dynamic stall can lead to adverse consequences such as reduced rotor thrust, increased rotor shaft torque, blade flutter, and increased vibration of the blade pitch control rod, which severely restrict the handling and safety performance of rotorcraft; while tip vortex interference can cause instability, aerodynamic efficiency loss, and noise problems.

[0004] Traditional blade tip opening control schemes (such as CN106741922A-A method for suppressing rotor noise based on swept blade tip openings, US20040197194A1-Rotor blade system with reduced blade-vortex interaction noise) severely weaken the structural strength because the openings are directly arranged in the blade tip, the weakest part of the structure and the most complex flow field (facing shock waves and blade tip vortex interference), making them difficult to apply in actual rotors.

[0005] There are two main approaches to solving these problems: passive flow control and active flow control. Passive flow control does not input energy from the outside; it only changes the aerodynamic shape of the wing to improve the aerodynamic force distribution. This method is relatively simple and mature in engineering applications, but it lacks flexibility, cannot be adjusted according to actual operating conditions, and cannot cope with real-time changing dynamic flow fields. Active flow control, on the other hand, can apply control only at localized sensitive points in the flow field without changing the aerodynamic shape, thereby altering the global flow field morphology and improving the wing's aerodynamic performance. By effectively controlling and utilizing the lift of dynamic stall vortices, flow control can mitigate the torque oscillations caused by the shedding of dynamic stall vortices, reduce the intensity of tip vortices or accelerate their dissipation, and reduce the high noise associated with tip vortices.

[0006] In active flow control, steady jet and cooperative jet systems typically require bleed air from the engine or a carrier air source, reducing the aircraft's net thrust and payload while increasing system integration complexity. Dielectric barrier discharge exciter control operates primarily in low-speed environments and struggles to achieve effective rotor flow field control under high-speed forward flight conditions.

[0007] Furthermore, current patents related to active flow control for rotors are all based on a single dynamic stall phenomenon or tip vortex, and there is no method that can be applied to both tip vortex control and dynamic stall vortex control simultaneously. In addition, tip vortices and dynamic stall vortices interact and influence each other, but there is currently no method that can coordinate the control of tip vortices and dynamic stall vortices. Summary of the Invention

[0008] The technical problem to be solved by this invention is to provide a device and method for the coordinated control of rotor tip vortex and dynamic stall vortex. By integrating two sets of synthetic jet exciters, one self-sustaining and the other pressurized, and utilizing the internally connected pressurization channel and valve system, coordinated and adjustable control of rotor tip vortex and dynamic stall vortex is achieved, which can effectively improve aerodynamic performance and suppress noise and vibration without the need for an external air source.

[0009] This invention provides a rotor tip vortex and dynamic stall vortex coordinated control device, including a self-sustaining synthetic jet exciter and a pressurized synthetic jet exciter;

[0010] The self-sustaining synthetic jet exciter includes a self-sustaining jet inlet located at the leading edge of the rotor tip, a self-sustaining jet outlet located at the tip face of the rotor tip, a self-sustaining jet channel located inside the rotor and connecting the self-sustaining jet inlet and the self-sustaining jet outlet, and a vibrating diaphragm I located inside the self-sustaining jet channel.

[0011] The pressurized synthetic jet exciter includes a pressurized jet outlet located on the upper surface of the rotor, a jet exciter cavity located inside the rotor, and a pressurized jet inlet connected to the jet exciter cavity.

[0012] It also includes a pressurization channel disposed inside the rotor and connecting the self-sustaining jet channel and the pressurized jet inlet, wherein a control valve I is disposed inside the pressurization channel;

[0013] A control valve II is installed on the self-sustaining jet inlet, and a one-way valve is installed inside the pressurized jet inlet.

[0014] Furthermore, multiple pressurized synthetic jet exciters are provided, and the pressurized jet outlets of the multiple pressurized synthetic jet exciters are distributed on the upper surface of the rotor.

[0015] Furthermore, the pressurized jet outlet is located upstream of the separation point of the dynamic stall vortex on the upper surface of the rotor.

[0016] Furthermore, the pressurized synthetic jet exciter is a synthetic dual-jet exciter, which has two pressurized jet outlets and two pressurized jet inlets.

[0017] Furthermore, multiple self-sustaining jet inlets are arranged at spanwise intervals;

[0018] The self-sustaining jet outlets are arranged at intervals along the chord direction.

[0019] Furthermore, the vibrating diaphragm I divides the self-sustaining jet channel into two independent cavities, and all self-sustaining jet inlets and outlets are connected to the two cavities.

[0020] Furthermore, the inlet of the pressurization channel is connected to one of the cavities of the self-sustaining jet channel, and the inlet is positioned directly opposite the vibrating diaphragm I.

[0021] Furthermore, the jet frequency of the self-sustaining synthetic jet exciter is coupled with the eigenfrequency of the tip vortex field.

[0022] Furthermore, a control valve III is provided at the outlet of the self-sustaining jet.

[0023] The present invention also provides a control method for the above-mentioned rotor tip vortex and dynamic stall vortex cooperative control device, including a tip vortex control mode, a dynamic stall vortex control mode and a cooperative control mode;

[0024] In the aforementioned tip vortex control mode: control valve I is in the closed state, the pressurized synthetic jet exciter is in the closed state, control valve II is in the open state, and the vibrating diaphragm I is in the working state;

[0025] Gas flows into the self-sustaining jet inlet and into the self-sustaining jet channel. The gas undergoes reciprocating vibration of the diaphragm I within the self-sustaining jet channel, giving the jet a frequency response characteristic. The jet with the frequency response characteristic flows out from the self-sustaining jet outlet. The jet with the frequency response characteristic couples with the eigenfrequency of the flow field, effectively controlling the formation and evolution of the tip vortex, weakening the tip vortex intensity, accelerating the dissipation speed of the tip vortex, and reducing the noise caused by the drastic changes in the local pressure field and the noise caused by the "paddle-vortex" interference that originally accompanied the formation and evolution of the tip vortex.

[0026] The dynamic stall vortex control mode includes a basic control mode and an enhanced control mode;

[0027] In the basic control mode, control valve I is closed, control valve II is closed, diaphragm I is closed, and the pressurized synthetic jet exciter is in operation. The pressurized synthetic jet exciter injects synthetic jet at the separation point of the dynamic stall phenomenon on the upper surface of the rotor. Through energy injection and induced vortex, the upper stopping point of the dynamic stall vortex is pushed forward, weakening the intensity of the dynamic stall vortex and maintaining the leading edge suction.

[0028] In the enhanced control mode, control valve I is in the open state, control valve II is in the open state, diaphragm I is in the closed state, and the pressurized synthetic jet exciter is in the working state. At this time, compared with the basic control mode, the pressurization channel will inject airflow into the jet exciter cavity to enhance the jet intensity ejected from the pressurized jet outlet, thereby improving the control effect of the dynamic stall vortex.

[0029] In the aforementioned coordinated control mode, control valve I is in the open state, control valve II is in the open state, vibrating diaphragm I is in the working state, and pressurized synthetic jet exciter is in the working state;

[0030] Simultaneously, the tip vortex control mode and the dynamic stall vortex control mode are implemented. By adjusting the opening of control valve I, the intensity ratio of the self-sustaining jet outlet and the pressurized jet outlet can be adjusted, thereby adjusting the tip vortex control intensity and the dynamic stall vortex control intensity.

[0031] The present invention has the following effects:

[0032] First, this invention effectively controls the dynamic stall vortex at the source of the flow field by arranging a pressurized synthetic jet exciter in the middle section of the upper wing surface, significantly reducing the intensity of unsteady disturbances transmitted to the blade tip and making the flow environment at the blade tip more stable. This reduces the structural strength requirements of the blade tip region, making it possible in engineering to apply a self-sustaining synthetic jet exciter to the blade tip for noise reduction and stabilization.

[0033] Second, it can realize three modes: tip vortex control, dynamic stall vortex control (basic / enhanced) and cooperative control. It can flexibly switch according to different flight conditions such as hovering, forward flight, take-off and landing, and realize the aerodynamic optimization of the rotorcraft from take-off to landing.

[0034] By adjusting the opening of the pressurization channel through control valve I, the intensity ratio of the self-sustaining jet to the pressurized jet can be adjusted in real time, thereby precisely distributing the control force on the tip vortex and the dynamic stall vortex. In the dynamic stall vortex enhancement control mode, opening this channel can inject additional airflow into the pressurized synthetic jet exciter, significantly improving its jet intensity and control effect, achieving a leap from basic control to enhanced control.

[0035] Third, the self-sustaining and pressurized exciters achieve airflow sharing and on-demand distribution through an internal pressurization channel. This design makes the system compact and highly integrated, and eliminates the need to bleed air from the engine or rely on an external air source, thus avoiding negative impacts on the aircraft's thrust and payload, and making it more widely applicable.

[0036] Fourth, during rotor rotation, the tip vortex or dynamic stall vortex detached from the previous cycle remains in the flow field. Its unsteady altitude characteristics severely interfere with subsequent blades, leading to aerodynamic instability and accompanied by loud noise. Furthermore, the detached dynamic stall vortex may meet and merge with the tip vortex, forming an even more complex interfering flow field. This invention addresses this by specifically controlling the two vortices: focusing on suppressing the dynamic stall vortex during forward flight and continuously weakening the tip vortex throughout all flight conditions. This effectively avoids mutual interference and coupling amplification between the two vortices, fundamentally improving flight safety and stability. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of the present invention;

[0038] Figure 2 This is a schematic diagram of the self-sustaining synthetic jet exciter in this invention;

[0039] Figure 3 for Figure 2 A magnified view of a section at point A in the middle;

[0040] Figure 4 This is a schematic diagram of the pressurized synthetic jet exciter in this invention;

[0041] Figure 5 This is a schematic diagram showing the connection between the self-sustaining synthetic jet exciter, the pressurization channel, and the intermediate pressurization synthetic jet exciter in this invention;

[0042] Figure 6 This is a schematic diagram of the propeller tip vortex control in this invention;

[0043] Figure 7 This is a schematic diagram of dynamic stall vortex control in this invention;

[0044] Figure 8 This is a schematic diagram showing the lift coefficient and its variation in the pressurized synthetic dual-jet control mode and the uncontrolled mode in this invention.

[0045] Figure 9 The pitching moment coefficient and its variation in the pressurized synthetic dual-jet control mode and the uncontrolled mode in this invention;

[0046] Figure 10 The diagram shows the pressure and Q-criteria during the first stall stage in the pressurized synthetic dual-jet control mode and the uncontrolled mode of this invention (the upper part shows the pressurized synthetic dual-jet control mode, and the lower part shows the uncontrolled mode).

[0047] Figure 11 The diagram shows the pressure and Q-criteria during the second stall stage in the pressurized synthetic dual-jet control mode and the uncontrolled mode of this invention (the upper part is the pressurized synthetic dual-jet control mode, and the lower part is the uncontrolled mode).

[0048] Figure 12 This is a diagram showing the pressure and Q-criteria during the third stall stage in the pressurized synthetic dual-jet control mode and the uncontrolled mode of this invention (the upper part is the pressurized synthetic dual-jet control mode, and the lower part is the uncontrolled mode).

[0049] In the figure, 1-Self-sustaining synthetic jet exciter; 11-Self-sustaining jet inlet; 111-Control valve II; 12-Self-sustaining jet outlet; 13-Self-sustaining jet channel; 14-Vibrating diaphragm I; 2-Pressurized synthetic jet exciter; 21-Pressurized jet outlet; 22-Jet exciter cavity; 23-Pressurized jet inlet; 231-One-way valve; 24-Vibrating diaphragm II; 3-Pressurized channel; 4-Control valve I; 5-Rotor; 51-Leading edge of rotor tip; 52-Tip surface of rotor tip; 53-Upper wing surface. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0051] 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.

[0052] 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 specified.

[0053] 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.

[0054] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0055] like Figures 1-12 As shown, the present invention provides a rotor tip vortex and dynamic stall vortex cooperative control device, including a self-sustaining synthetic jet exciter 1 and a pressurized synthetic jet exciter 2;

[0056] The self-sustaining synthetic jet exciter 1 includes a self-sustaining jet inlet 11 arranged at the leading edge 51 of the rotor tip 5, a self-sustaining jet outlet 12 arranged at the tip face 52 of the rotor 5, a self-sustaining jet channel 13 arranged inside the rotor 5 and connecting the self-sustaining jet inlet 11 and the self-sustaining jet outlet 12, and a vibrating diaphragm I 14 arranged inside the self-sustaining jet channel 13.

[0057] The pressurized synthetic jet exciter 2 includes a pressurized jet outlet 21 arranged on the upper wing surface 53 of the rotor 5, a jet exciter cavity 22 disposed in the rotor 5, and a pressurized jet inlet 23 connected to the jet exciter cavity 22. A vibrating diaphragm II 24 is disposed inside the jet exciter cavity 22. When the pressurized jet inlet 23 is closed and no gas is injected into the jet exciter cavity 22, the vibrating diaphragm II 24 vibrates back and forth, which causes the pressurized jet outlet 21 to form an alternating suction and suction jet. When the pressurized jet inlet 23 is open and gas is injected into the jet exciter cavity 22, the vibrating diaphragm II 24 vibrates back and forth, which ejects the gas in the jet exciter cavity 22 from the pressurized jet outlet 21 at a specific frequency.

[0058] refer to Figure 5 It also includes a pressurization channel 3 disposed inside the rotor 5 and connected to the self-supporting jet channel 13 and the pressurized jet inlet 23. The pressurization channel 3 is provided with a control valve I4, which can adjust the opening of the pressurization channel 3 from fully open to fully closed.

[0059] A control valve II 111 is provided on the self-sustaining jet inlet 11. The control valve II 111 can adjust the opening and closing of the self-sustaining jet inlet 11. Preferably, the control valve II 111 adopts a one-way valve structure to control the one-way flow of the self-sustaining jet inlet 11. A one-way valve 231 is provided in the pressurized jet inlet 23. The one-way valve 231 makes the airflow only flow from the pressurized channel 3 into the pressurized jet inlet 23, and cannot flow from the pressurized jet inlet 23 to the pressurized channel 3.

[0060] The present invention also provides a control method for the above-mentioned rotor tip vortex and dynamic stall vortex cooperative control device, including a tip vortex control mode, a dynamic stall vortex control mode and a cooperative control mode;

[0061] In the aforementioned tip vortex control mode: control valve I4 is in the closed state, pressurized synthetic jet exciter 2 is in the closed state, control valve II111 is in the open state, and vibrating diaphragm I14 is in the working state.

[0062] Gas flows into the self-sustaining jet inlet 11 and into the self-sustaining jet channel 13. The gas in the self-sustaining jet channel 13 is subjected to the reciprocating vibration of the vibrating diaphragm I 14, which gives the jet a frequency response characteristic. The jet with the frequency response characteristic flows out from the self-sustaining jet outlet 12. The jet with the frequency response characteristic is coupled with the eigenfrequency of the flow field, which effectively controls the formation and evolution process of the tip vortex, weakens the intensity of the tip vortex, accelerates the dissipation speed of the tip vortex, and reduces the noise caused by the drastic changes in the local pressure field and the noise caused by the "paddle-vortex" interference that originally accompanied the formation and evolution process of the tip vortex.

[0063] The dynamic stall vortex control mode includes a basic control mode and an enhanced control mode;

[0064] In the basic control mode, control valve I4 is closed, control valve II111 is closed, diaphragm I14 is closed, and pressurized synthetic jet exciter 2 is in operation. Pressurized synthetic jet exciter 2 injects synthetic jet at the separation point of dynamic stall phenomenon on the upper surface 53 of rotor 5. Through energy injection and induced vortex, the upper stopping point of dynamic stall vortex is pushed, weakening the intensity of dynamic stall vortex and maintaining leading edge suction.

[0065] In the enhanced control mode, control valve I4 is in the open state, control valve II111 is in the open state, diaphragm I14 is in the closed state, and pressurized synthetic jet exciter 2 is in the working state. At this time, compared with the basic control mode, pressurized channel 3 will inject airflow into jet exciter cavity 22 to enhance the jet intensity ejected from pressurized jet outlet 21, thereby improving the control effect of dynamic stall vortex.

[0066] In the aforementioned coordinated control mode, control valve I4 is in the open state, control valve II111 is in the open state, vibrating diaphragm I14 is in the working state, and pressurized synthetic jet exciter 2 is in the working state.

[0067] Simultaneously, the tip vortex control mode and the dynamic stall vortex control mode are implemented. By adjusting the opening of control valve I4, the intensity ratio of the self-sustaining jet outlet 12 and the pressurized jet outlet 21 can be adjusted, thereby adjusting the tip vortex control intensity and the dynamic stall vortex control intensity.

[0068] The rotor tip vortex and dynamic stall vortex coordinated control device and method provided by the present invention have the following effects:

[0069] First, traditional rotor tip orifice control schemes (such as CN106741922A - A rotor noise suppression method based on swept rotor tip orifice, US20040197194A1 - Rotor blade system with reduced blade-vortex interaction noise) severely weaken structural strength because the orifice is directly placed in the rotor tip, the weakest structural area with the most complex flow field (facing shock waves and rotor tip vortex interference), making them difficult to apply in actual rotors. This invention, by arranging a pressurized synthetic jet exciter 2 in the middle section of the upper wing surface 53, effectively controls the dynamic stall vortex from the flow field source, significantly reducing the intensity of unsteady interference transmitted to the rotor tip and stabilizing the flow environment at the rotor tip. This reduces the structural strength requirements of the rotor tip region, making it possible in engineering to apply a self-sustaining synthetic jet exciter to the rotor tip for noise reduction and stabilization.

[0070] Second, it can realize three modes: tip vortex control, dynamic stall vortex control (basic / enhanced) and cooperative control. It can flexibly switch according to different flight conditions such as hovering, forward flight, take-off and landing, and realize the aerodynamic optimization of the rotorcraft from take-off to landing.

[0071] By adjusting the opening of the booster channel 3 through control valve I4, the intensity ratio of the self-sustaining jet and the booster jet can be adjusted in real time, thereby precisely distributing the control force on the tip vortex and the dynamic stall vortex. In the dynamic stall vortex enhancement control mode, opening this channel can inject additional airflow into the booster synthetic jet exciter 2, significantly improving its jet intensity and control effect, achieving a leap from basic control to enhanced control.

[0072] Third, the self-sustaining and pressurized exciters achieve airflow sharing and on-demand distribution through the internal pressurization channel 3. This design makes the system compact and highly integrated, and eliminates the need to draw air from the engine or rely on an external air source, thus avoiding negative impacts on the aircraft's thrust and payload, and making it more widely applicable.

[0073] Fourth, during rotor rotation, the tip vortex or dynamic stall vortex detached from the previous cycle remains in the flow field. Its unsteady altitude characteristics severely interfere with subsequent blades, leading to aerodynamic instability and accompanied by loud noise. Furthermore, the detached dynamic stall vortex may meet and merge with the tip vortex, forming a more complex interfering flow field. This invention addresses this by specifically controlling the two vortices: focusing on suppressing the dynamic stall vortex during forward flight and continuously weakening the tip vortex throughout all flight conditions. This effectively avoids mutual interference and coupling amplification between the two vortices, fundamentally improving flight safety and stability.

[0074] In one embodiment, the control valve II111 is preferably a one-way valve, in which case the tip vortex can be continuously reduced under all operating conditions.

[0075] In one embodiment, reference Figure 1 Multiple pressurized synthetic jet exciters 2 are provided, and the pressurized jet outlets 21 of the multiple pressurized synthetic jet exciters 2 are distributed on the upper wing surface 53 of the rotor 5. Specifically, the optimal arrangement position of the multiple pressurized jet outlets 21 can be determined by determining the dynamic stall vortex formation, development, evolution and shedding process under different dynamic stall degrees and by using the flow field results under different dynamic stall degrees.

[0076] In one embodiment, the pressurized jet outlet 21 is located upstream of the separation point of the dynamic stall vortex on the upper surface 53 of the rotor 5. This arrangement enables source intervention and efficient suppression of the dynamic stall process. Specifically, applying a periodic jet in the critical region where the flow is about to separate but has not yet separated allows for the early injection of high-energy gas into the boundary layer, significantly enhancing the kinetic energy of the near-wall fluid. This directly delays or inhibits the initiation of flow separation, weakening the generation intensity of the dynamic stall vortex at its source. The high-frequency synthetic jet ejected from this location can induce a series of controllable, small-scale vortex structures in the main flow. These induced vortices can unsteadily interact with the developing dynamic stall vortex, effectively cutting or combing through large-scale vortex structures, disrupting their orderly development, and causing them to adhere to the upper surface 53 for a longer period. This fully utilizes the unsteady vortex lift and delays its breakup and detachment. Through the above mechanism, this arrangement can not only effectively maintain the peak suction of the wing leading edge and improve lift, but also significantly suppress pitch torque oscillation caused by the violent shedding of dynamic stall vortex, greatly improving the aerodynamic environment and handling stability of the rotor blade 5.

[0077] In one embodiment, reference Figure 4 and Figure 5 The pressurized synthetic jet exciter 2 is a synthetic dual-jet exciter, which has two pressurized jet outlets 21 and two pressurized jet inlets 23. In this embodiment, the synthetic dual-jet exciter can greatly improve the utilization rate of the vibrating diaphragm II 24, enabling one vibrating diaphragm II 24 to work on two sets of jet exciter cavities 22, pressurized jet outlets 21 and pressurized jet inlets 23, thereby doubling the jet intensity. Moreover, the two pressurized jet outlets 21 alternately inject jets, ensuring that there is always jet injected into the upper wing surface 53 of the rotor 5 at any time.

[0078] In one embodiment, reference Figure 1 The self-sustaining jet inlets 11 are arranged at intervals along the spanwise direction;

[0079] The self-sustaining jet outlets 12 are arranged in multiple chordally.

[0080] In this embodiment, multiple self-sustaining jet inlets 11 distributed along the spanwise direction can collaboratively draw in incoming flow from different radial positions at the leading edge of the propeller tip, ensuring the uniformity of pressure and energy acquisition. Meanwhile, multiple self-sustaining jet outlets 12 distributed along the chordwise direction can simultaneously release controlled jets at different flow directions at the propeller tip. This arrangement constitutes a control surface covering the three-dimensional space of the propeller tip, enabling simultaneous, encircling intervention of the vortex core and its development path at multiple points, thereby achieving more comprehensive and thorough vortex structure dissipation and fragmentation than single-point control.

[0081] Furthermore, the distributed layout of the self-sustaining jet inlets 11 and self-sustaining jet outlets 12 introduces redundancy. When the performance of some self-sustaining jet inlets 11 or self-sustaining jet outlets 12 deteriorates due to contamination or damage, the remaining normally functioning units can still maintain a considerable degree of control effectiveness, greatly improving the system's fault tolerance and task reliability under complex operating conditions. Simultaneously, the collaborative operation of multiple self-sustaining jet outlets 12 can effectively compensate for potential directional deviations or uneven intensity of the jet from a single self-sustaining jet outlet 12, ensuring global consistency and stability of the control effect.

[0082] By distributing the total airflow demand across multiple small-sized self-sustaining jet inlets 11 and self-sustaining jet outlets 12, the potential for localized flow separation or additional drag caused by large-scale suction and ejection at a single location is avoided. This minimizes the interference of control actions on the main flow field of the blades, effectively suppressing tip vortices while maximizing the preservation of the original aerodynamic performance of the blades.

[0083] In one embodiment, reference Figure 3 and Figure 5 The vibrating diaphragm I 14 divides the self-sustaining jet channel 13 into two independent cavities, and all self-sustaining jet inlets 11 and self-sustaining jet outlets 12 are connected to the two cavities. Preferably, both the self-sustaining jet inlets 11 and self-sustaining jet outlets 12 are channel structures, with the ends of the channels merging with the two cavities. The self-sustaining jet inlets 11 and self-sustaining jet outlets 12 utilize pressure difference to form a self-sustaining jet flowing from the self-sustaining jet inlets 11 to the self-sustaining jet outlets 12.

[0084] In this embodiment, the structure makes the self-sustaining synthetic jet exciter 1 essentially a dual-acting pump. When the vibrating diaphragm I 14 reciprocates, the volume changes of the two chambers are in opposite phases, so that when one chamber is in the jet (blowing) phase, the other chamber is in the suction phase. This inverse relationship significantly increases the net mass flow rate through the outlet and generates a more continuous synthetic jet with higher momentum, effectively overcoming the dead zone of zero net mass flow rate in a single cycle of traditional single-chamber synthetic jets, thus directly impacting and breaking the tip vortex with higher efficiency. The self-sustaining jet inlet 11 and the self-sustaining jet outlet 12 simultaneously connect the two chambers, forming a highly efficient airflow circulation loop inside. The minute vibration of the vibrating diaphragm I 14 can generate strong internal airflow oscillations within this loop, which are strictly synchronized with the diaphragm vibration frequency. This design prioritizes energy in establishing and maintaining high-frequency pressure pulsations within the channel, allowing the airflow exiting the outlet to carry extremely strong and pure specific frequencies. This enables more precise and efficient resonant coupling with the intrinsic frequencies of the tip vortex field, fundamentally optimizing the efficiency of active control over the tip vortex.

[0085] In one embodiment, reference Figure 3The inlet of the pressurization channel 3 is connected to one of the cavities of the self-supporting jet channel 13, and the inlet is positioned directly opposite the vibrating diaphragm I14.

[0086] In this embodiment, the layout places the inlet of the pressurization channel 3 directly on the "impact surface" of the reciprocating diaphragm I14. When the control valve I4 is opened, each strong vibration of the diaphragm I14 directionally and pulsarily "pumps" the high-pressure gas in its cavity into the pressurization channel 3. This provides the downstream pressurized synthetic jet exciter 2 with an airflow that is far more pulsating than that driven by static pressure difference, thereby significantly enhancing the peak velocity and momentum of the jet ejected from the pressurized jet outlet 21 and greatly improving the control effect of the dynamic stall vortex.

[0087] In this embodiment, a portion of the mechanical work of the vibrating diaphragm I14 of the self-sustaining synthetic jet exciter 1 is cleverly transferred to the pressurized synthetic jet exciter 2 through airflow pulsation, serving as an additional energy source for its "enhanced control mode". This achieves energy and actuation synergy between the two independent exciters, rather than simple airflow connection, maximizing the overall energy utilization efficiency and control effectiveness of the system.

[0088] Furthermore, since the inlet of the pressurization channel 3 is directly opposite the vibrating diaphragm I14, and the pressure wave generated by the vibration of the vibrating diaphragm I14 dominates the flow direction at that point, this helps ensure that the airflow stably flows from the self-sustaining jet channel 13 into the pressurization channel 3. Combined with the one-way valve 231 inside the pressurized jet inlet 23, a reliable one-way flow system is formed, effectively preventing pressure fluctuations within the chamber of the pressurized synthetic jet exciter 2 from interfering with the normal operation of the self-sustaining synthetic jet exciter 1, and ensuring the stability of independent and coordinated operation of each mode.

[0089] In one embodiment, the jet frequency of the self-sustaining synthetic jet exciter 1 is coupled to the eigenfrequency of the tip vortex flow field. In this embodiment, when the frequency of the self-sustaining jet matches the inherent shedding or evolution frequency of the tip vortex, minute periodic disturbances can be amplified by the flow field through resonance. This allows the jet energy to be injected into the unstable mode of the tip vortex most accurately and effectively, thereby significantly accelerating its fragmentation and dissipation process, achieving optimal control with minimal control energy.

[0090] In one embodiment, a control valve III (not shown in the figure) is provided at the self-sustaining jet outlet 12. In this embodiment, the outlet area or opening / closing state of the self-sustaining jet can be adjusted by the control valve III. This allows the system to dynamically control the jet intensity and the number of effective outlets. In conditions where the tip vortex is weak or full control is not required, the opening can be reduced or some outlets can be closed to save energy; in conditions requiring strong control, they can be fully opened to achieve maximum efficiency. Combined with the layout of multiple outlets, this design even allows for differentiated control strategies to be implemented for different areas of the tip, improving control accuracy.

[0091] refer to Figures 8-9 Figure 1 shows the changes in lift coefficient and moment coefficient before and after using the pressurized synthetic jet exciter control. After adopting pressurized synthetic jet control, the lift coefficient significantly improved. This indicates that the control effectively suppressed the stall phenomenon, thus restoring aerodynamic forces. For the moment coefficient, the curve shape changed from "∞" to a counter-clockwise rotating "o" loop, indicating that the pressurized synthetic jet exciter control enhanced rotor stability.

[0092] refer to Figures 10-12 The diagram shows the pressure and Q-criteria at three different stages before and after using a pressurized synthetic dual-jet exciter for control. Q represents the vortex. After control, vortex shedding and large separation phenomena are suppressed, vortices tend to adhere to the rotor surface, and stall is controlled. In addition, the leading-edge negative pressure is enhanced, indicating that the aerodynamics during the stall stage is improved, and the control plays a role in increasing speed and reducing drag.

[0093] The above description is merely an embodiment and does not constitute any limitation on the present invention. Any person skilled in the art can make many possible variations, modifications, or alterations to the technical solutions of the present invention without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, should fall within the protection scope of the present invention.

Claims

1. A control method for a rotor tip vortex and dynamic stall vortex coordinated control device, characterized in that, The rotor tip vortex and dynamic stall vortex coordinated control device is used, which includes a self-sustaining synthetic jet exciter (1) and a pressurized synthetic jet exciter (2). The self-sustaining synthetic jet exciter (1) includes a self-sustaining jet inlet (11) arranged at the leading edge (51) of the rotor (5), a self-sustaining jet outlet (12) arranged at the tip face (52) of the rotor (5), a self-sustaining jet channel (13) arranged inside the rotor (5) and connecting the self-sustaining jet inlet (11) and the self-sustaining jet outlet (12), and a vibrating diaphragm I (14) arranged inside the self-sustaining jet channel (13). The pressurized synthetic jet exciter (2) includes a pressurized jet outlet (21) arranged on the upper wing surface (53) of the rotor (5), a jet exciter cavity (22) arranged in the rotor (5), and a pressurized jet inlet (23) connected to the jet exciter cavity (22). It also includes a pressurization channel (3) disposed inside the rotor (5) and connecting the self-sustaining jet channel (13) and the pressurized jet inlet (23), wherein a control valve I (4) is disposed inside the pressurization channel (3); A control valve II (111) is provided on the self-sustaining jet inlet (11), and a one-way valve (231) is provided inside the pressurized jet inlet (23). The control methods include tip vortex control mode, dynamic stall vortex control mode, and cooperative control mode. In the aforementioned tip vortex control mode: control valve I (4) is in the closed state, pressurized synthetic jet exciter (2) is in the closed state, control valve II (111) is in the open state, and vibrating diaphragm I (14) is in the working state; Gas flows into the self-sustaining jet inlet (11) and into the self-sustaining jet channel (13). The gas in the self-sustaining jet channel (13) is subjected to the reciprocating vibration of the diaphragm I (14), which gives the jet frequency response characteristics. The jet with frequency response characteristics flows out from the self-sustaining jet outlet (12). The jet with frequency response characteristics is coupled with the intrinsic frequency of the flow field, effectively controlling the formation and evolution of the tip vortex, weakening the tip vortex intensity, accelerating the dissipation speed of the tip vortex, and reducing the noise caused by the drastic changes in the local pressure field and the noise caused by the "paddle-vortex" interference that originally accompanied the formation and evolution of the tip vortex. The dynamic stall vortex control mode includes a basic control mode and an enhanced control mode; In the basic control mode, control valve I (4) is closed, control valve II (111) is closed, diaphragm I (14) is closed, and booster synthetic jet exciter (2) is in working state. The booster synthetic jet exciter (2) injects synthetic jet at the separation point of dynamic stall phenomenon on the upper surface (53) of rotor (5). Through energy injection and induced vortex, the upper stop point of dynamic stall vortex is pushed, weakening the intensity of dynamic stall vortex and maintaining leading edge suction. In the enhanced control mode, control valve I (4) is in the open state, control valve II (111) is in the open state, diaphragm I (14) is in the closed state, and boosted synthetic jet exciter (2) is in the working state. At this time, compared with the basic control mode, the boosted channel (3) will inject airflow into the jet exciter cavity (22) to enhance the jet intensity ejected from the boosted jet outlet (21), thereby improving the control effect of dynamic stall vortex. In the aforementioned coordinated control mode, control valve I (4) is in the open state, control valve II (111) is in the open state, diaphragm I (14) is in the working state, and pressurized synthetic jet exciter (2) is in the working state. Simultaneously, the tip vortex control mode and the dynamic stall vortex control mode are carried out. By adjusting the opening of the control valve I (4), the intensity ratio of the self-sustaining jet outlet (12) and the pressurized jet outlet (21) can be adjusted, thereby adjusting the tip vortex control intensity and the dynamic stall vortex control intensity.

2. The control method of the rotor tip vortex and dynamic stall vortex cooperative control device as described in claim 1, characterized in that, The pressurized synthetic jet exciter (2) is provided in multiple ways, and the pressurized jet outlets (21) of the multiple pressurized synthetic jet exciters (2) are distributed on the upper wing surface (53) of the rotor (5).

3. The control method of the rotor tip vortex and dynamic stall vortex cooperative control device as described in claim 1, characterized in that, The pressurized jet outlet (21) is located upstream of the separation point of the dynamic stall vortex on the upper surface (53) of the rotor (5).

4. The control method of the rotor tip vortex and dynamic stall vortex cooperative control device as described in claim 1, characterized in that, The pressurized synthetic jet exciter (2) is a synthetic dual jet exciter, which has two pressurized jet outlets (21) and two pressurized jet inlets (23).

5. The control method of the rotor tip vortex and dynamic stall vortex cooperative control device as described in any one of claims 1-4, characterized in that, The self-sustaining jet inlet (11) is arranged in multiple intervals along the spanwise direction; The self-sustaining jet outlet (12) is arranged in multiple chordally.

6. The control method of the rotor tip vortex and dynamic stall vortex cooperative control device as described in claim 5, characterized in that, The vibrating diaphragm I (14) divides the self-sustaining jet channel (13) into two independent cavities, and all self-sustaining jet inlets (11) and self-sustaining jet outlets (12) are connected to the two cavities.

7. The control method of the rotor tip vortex and dynamic stall vortex cooperative control device as described in claim 6, characterized in that, The inlet of the pressurization channel (3) is connected to one of the cavities of the self-sustaining jet channel (13), and the inlet is positioned directly opposite the vibrating diaphragm I (14).

8. The control method of the rotor tip vortex and dynamic stall vortex cooperative control device as described in claim 5, characterized in that, The jet frequency of the self-sustaining synthetic jet exciter (1) is coupled with the intrinsic frequency of the tip vortex field.

9. The control method of the rotor tip vortex and dynamic stall vortex cooperative control device as described in any one of claims 1-4 and 6-8, characterized in that, A control valve Ⅲ is provided at the self-sustaining jet outlet (12).

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