Multi-mode wide adaptability active flow control actuator and control method thereof

Abstract

The present invention provides a multi-modal wide adaptability novel active flow control actuator and a control method thereof, including an oscillating jet actuator and a zero-mass jet actuator, wherein the zero-mass jet actuator is arranged between two inner flow paths of the oscillating jet actuator; an opening is respectively arranged on the splitting position of the two inner flow paths of the oscillating jet actuator and the inner side walls on both sides, connecting the outlet of the zero-mass jet actuator; an air supply inlet and two control ports are arranged at the top of the oscillating jet actuator, the air supply inlet is connected to the air source through the air supply pipeline, the air supply pipeline is provided with a main valve, and the main valve controls the air source to provide high-pressure or low-pressure gas; an outlet is respectively arranged at the bottom of the two inner flow paths, connecting the outside of the controlled aerodynamic profile wall. The present invention organically combines the three active flow modes of zero-mass synthetic jet, oscillating jet and micro-suction, gives full play to their respective advantages, and enables the actuator to have multiple modes, which can be controlled according to different flight conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of active flow control, and in particular relates to a multi-modal wide-adaptability active flow control actuator and a control method thereof. Background Art

[0002] As a pioneer in the design of aerospace vehicles, the excellence of aerodynamic characteristics of aerodynamic technology directly determines the overall performance level of aerospace vehicles. At the same time, with the continuous development and progress of aerospace vehicles, their performance improvement is highly dependent on excellent aerodynamic shape design and efficient flow control technology. Among them, flow control changes the original flow state by applying or changing physical quantities such as force, mass, thermal energy, and electromagnetics to the moving fluid, so that the distribution of flow in time and space meets the required requirements. Its functions and purposes may include: controlling the delay / advance of boundary layer transition, suppressing / enhancing turbulence, preventing / promoting separation, increasing lift and reducing drag, enhancing mixing or heat transfer, and suppressing flow-induced noise.

[0003] Over the years, active flow control technology has become the forefront and hot spot of current fluid mechanics and aerospace research due to its promising prospect of "making a big difference with a small effort". After years of vigorous development, a large number of research results have been accumulated, but there is still a certain gap from the needs of engineering applications. The main problems and difficulties it faces are how to further improve the scope of use of flow control in different working conditions, adaptability, flow control efficiency and cost-effectiveness.

[0004] At present, active flow control methods can be divided into oscillating jets, zero-mass excitation synthetic jets, (continuous or intermittent) blowing / inhaling, direct control of geometric shape changes, jet vortex generators, electromagnetic / plasma, geometric and pneumatic combination or mixed control, etc., according to the type of their core component actuators. Different active flow control methods are mostly adapted to different operating conditions or single flow control purposes, resulting in insufficient application scope and adaptability, and limited overall cost-effectiveness. Therefore, it is urgent to develop multi-modal active flow control methods with a wider range of applications. Scholars at home and abroad have begun to study related work. For example, Gu Yunsong and others from Nanjing University of Aeronautics and Astronautics used zero-mass jets to drive and control the practical frequency of oscillating jets, thereby expanding the speed range of oscillating jet actuators. Luo Zhenbing and others from the National University of Defense Technology combined passive flow control with active flow control to achieve the effect of improving the wide envelope of flow control and variable working conditions. Summary of the invention

[0005] In response to the technical problems of insufficient application scope and adaptability of active flow control methods in the prior art, the present invention provides a multi-modal, widely adaptable active flow control actuator and a control method thereof, which combines the advantages of existing active flow control technologies to achieve dual expansion of active flow control capability and application scope and multi-point improvement of full flight envelope performance, thereby meeting the urgent needs of large aspect ratio aircraft for aerodynamic performance.

[0006] In order to solve the technical problems existing in the prior art, the present invention provides a multi-modal wide-adaptability active flow control actuator, including an oscillating jet actuator and a zero-mass jet actuator, wherein the zero-mass jet actuator is arranged between two internal flow paths of the oscillating jet actuator; an opening is respectively arranged on the splitting position of the two internal flow paths of the oscillating jet actuator and the inner walls on both sides, connecting the outlet of the zero-mass jet actuator; an air supply inlet and two control ports are arranged at the top of the oscillating jet actuator, the air supply inlet is connected to the air source through the air supply pipeline, the air supply pipeline is provided with a main valve, and the main valve controls the air source to provide high-pressure or low-pressure gas; an outlet is respectively arranged at the bottom of the two internal flow paths, connecting to the outside of the controlled pneumatic surface wall.

[0007] Further, the massless jet exciter is three small exciters, and the outlets correspond to the opening positions; or the massless jet exciter is one large exciter, and has three outlets corresponding to the opening positions.

[0008] Furthermore, the control port is located outside the main side wall of the oscillating jet actuator and is used to control the basic operating frequency of the oscillating jet.

[0009] Furthermore, the active flow control actuator is embedded in the wall surface of the controlled pneumatic profile by means of direct built-in embedding.

[0010] Furthermore, the active flow control actuators are multiple and arranged at different positions on the pneumatic surface. Each active flow control actuator is connected to the air source supply pipeline through a branch pipeline, and a sub-valve is also provided on each branch pipeline.

[0011] The present invention also provides a multi-modal wide adaptability active flow control actuator control method, the specific control method is as follows:

[0012] The main valve is closed, the zero-mass jet actuator is started, and the zero-mass jet actuator works alone;

[0013] The main valve is opened, the zero-mass jet actuator is not started, and the main valve of the air supply pipeline is controlled to be in high-pressure condition, which is the single working mode of oscillating jet flow control;

[0014] The main valve is opened, the zero-mass jet actuator is not started, and the main valve of the air supply pipeline is controlled to be in a low-pressure condition, which is a separate working mode for micro-suction flow control;

[0015] The main valve is opened, the zero-mass jet actuator is started, and the main valve of the air supply pipeline is controlled to be under high-pressure conditions, which is a combined working mode of oscillating jet flow control and zero-mass jet actuator;

[0016] The main valve is opened, the zero-mass jet actuator is started, and the main valve of the air supply pipeline is controlled to be in a low-pressure condition, which is a combined working mode of micro-suction flow control and zero-mass jet actuator;

[0017] Select the appropriate working mode according to different flight conditions.

[0018] Furthermore, at least two active flow control actuators are arranged at different positions on the pneumatic surface. Each active flow control actuator is connected to the air source supply pipeline through a branch pipeline. A sub-valve is set on each branch pipeline to control the main valve to close and the sub-valve to open. Airflow is formed between multiple active flow control actuators due to the local pressure difference to control the working mode.

[0019] Further, at least one active flow control actuator is arranged at the leading edge of the wing.

[0020] The beneficial effects of the present invention compared with the prior art are as follows:

[0021] The multi-modal wide adaptability active flow control actuator and control method thereof proposed by the present invention have the following advantages

[0022] ① Through a set of multi-modal active flow control actuators, the control functions that originally required multiple sets of different conventional flow control systems to complete are realized, effectively expanding the adaptability of the flow control system in the flight envelope of high-speed airspace, and greatly improving the engineering application capabilities.

[0023] ② By combining high-energy exciters (oscillating jets, etc.) and low-energy exciters (zero-mass synthetic jets, intermittent micro-suction, etc.) modally, individual modal or combined modal flow control can be performed according to the specific conditions of different operating conditions, thereby improving the real-time cost-effectiveness of flow control.

[0024] ③ Use the air supply pipeline from the high-pressure area near the stagnation point such as the leading edge of the wing to bleed air to the exciter in other areas to provide a certain quality of high-pressure energy airflow, thereby reducing the energy input and flow thrust loss required to bleed air from the engine in the case of larger (medium) mass jets.

[0025] ④ The gas supply main line and control system can be shared, which can greatly reduce the structural weight and other usage costs compared to three separate systems.

[0026] ⑤ When taking off or circling at low speed, the lift coefficient and stall angle of attack need to be greatly increased. A zero-mass synthetic jet can be used to excite / drive the oscillating jet variable frequency working mode to obtain the maximum jet velocity, improve the large separation flow, effectively delay the stall, and increase the available lift coefficient.

[0027] ⑥ During the cruise phase, the front half of the aerodynamic profile in the approaching flow direction mainly adopts the micro-suction mode to control and delay the laminar transition and reduce friction resistance; the rear half of the aerodynamic profile mainly adopts the zero-mass synthetic jet mode to control the trailing edge separation, reduce the drag, achieve comprehensive drag reduction of laminar / turbulent mixed flow, and improve the cruise lift-to-drag ratio and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0029] Figure 1 A schematic diagram of the structure of a multi-modal wide-adaptability active flow control actuator provided by a specific embodiment of the present invention;

[0030] Figure 2 A schematic diagram of another multi-modal wide-adaptability active flow control actuator structure provided by a specific embodiment of the present invention;

[0031] Figure 3 The individual / combined working modes of the multi-modal wide-adaptability active flow control actuator provided in the specific embodiment of the present invention.

[0032] The above drawings include the following reference numerals:

[0033] 1—the outlet of the second zero-mass jet actuator; 2—the inner flow path of the oscillating jet actuator; 3—the outlet of the first zero-mass jet actuator; 4—the control port of the oscillating jet actuator; 5—the air supply inlet of the actuator; 6—the outlet of the actuator; 7—the zero-mass jet actuator; 8—the controlled pneumatic profile wall; 9—the outlet of the third zero-mass jet actuator; 10—the main side wall of the oscillating jet actuator; 11—the diverter of the oscillating jet actuator; 12—the first sub-valve; 13—the air supply pipeline; 14—the main valve of the air supply pipeline; 15—the branch pipeline; 16—the second sub-valve. DETAILED DESCRIPTION

[0034] Specific embodiments of the present invention are described in detail below. In the following description, for the purpose of explanation and not limitation, specific details are set forth to help fully understand the present invention. However, it will be apparent to those skilled in the art that the present invention may also be practiced in other embodiments that depart from these specific details.

[0035] It should be noted that in order to avoid obscuring the present invention due to unnecessary details, only the device structure and / or processing steps closely related to the scheme of the present invention are shown in the drawings, while other details that are not closely related to the present invention are omitted.

[0036] The present invention organically combines the three existing active flow control methods of zero-mass synthetic jet, oscillating jet and micro-suction, takes advantage of each other, and gives full play to their respective advantages to design a multi-modal wide-adaptability active flow control actuator:

[0037] (1) A multi-opening zero-mass synthetic jet actuator or multiple zero-mass synthetic jet actuators are arranged inside the oscillating jet actuator component structure, and the zero-mass synthetic jet is used to excite / drive the oscillating jet frequency conversion, thereby achieving a significant increase in the wide-speed range operating frequency and jet velocity range.

[0038] (2) The valve of the main line of the oscillating jet gas source is used to adjust the airflow pressure of each branch to realize intermittent micro-suction function and related control of some circuits. By combining with the zero-mass synthetic jet and oscillating jet components, a multi-modal actuator system is formed in which the three can work separately and independently and can work in combination with each other.

[0039] (3) An exciter is arranged at a stationary point at the leading edge of the wing and combined with exciters at other positions on the wing. Air bleed from a high-pressure area near the stationary point at the leading edge of the wing is used to provide a certain quality of high-pressure airflow for the air supply pipelines of exciters in other areas, thereby reducing the energy input and flow thrust loss required to bleed air from the engine in the case of a large (medium) quality jet. This allows the ability to provide different jet quality controls for different operating conditions at the lowest overall cost.

[0040] In this embodiment, the multi-modal wide adaptability active flow control actuator is composed of three active flow mode actuators (pipelines): zero-mass synthetic jet, oscillating jet and micro-suction air. Figure 1As shown, it mainly includes an oscillating jet actuator, a zero-mass jet actuator, an airflow pipeline, and a control valve. The massless jet exciter is arranged between the two inner flow paths of the oscillating jet exciter. An opening is respectively arranged at the position of the splitter 11 of the two inner flow paths 2 of the oscillating jet exciter and on the inner side walls on both sides, which are used to connect the outlet of the massless jet exciter 7; a combined exciter air supply inlet 5 and two oscillating jet exciter control ports 4 are arranged at the top of the oscillating jet exciter, the air supply inlet 5 is connected to the air source through the air supply pipeline, the combined exciter air supply inlet 5 connects the inner flow path and the external air source, the air supply pipeline is provided with a main valve, and the main valve controls the air source to output high-pressure gas and low-pressure gas; the oscillating jet exciter control port 4 is located on the outside of the main side wall 10 of the oscillating jet exciter, and can control the basic working frequency of the oscillating jet; a multi-modal combined exciter outlet 6 is respectively arranged at the bottom end of the two inner flow paths 2, and the multi-modal combined exciter outlet 6 is connected to the outside of the controlled pneumatic surface wall 8; the active flow control exciter is embedded in the controlled pneumatic surface wall 8 by direct built-in inlay, and the exciter outlet is arranged on the wall 8.

[0041] The inner cavity and the pipe wall of the oscillating jet exciter of the present invention constitute the main structure of the multi-mode exciter, the inner flow path 2 of the oscillating jet exciter, the control port 4 of the oscillating jet exciter, the main side wall 10 of the oscillating jet exciter, and the splitter 11 of the oscillating jet exciter. The zero-mass jet exciter 7 is mainly distributed in the area surrounded by the inner flow channel 2 and the splitter 11 on both sides of the oscillating jet exciter, such as Figure 1 As shown, the three outlets 1, 3, and 9 of the zero-mass jet exciter 7 are arranged at corresponding positions. The zero-mass jet exciter 7 can be arranged in a manner of three small exciters, or it can be arranged in a manner of a large exciter with three outlets at corresponding positions, such as Figure 2 Among them, the first zero-mass jet actuator outlet 3 is mainly used for working in combination with the oscillating jet, and the first, second and third zero-mass jet actuator outlets are mainly used for implementing disturbance control on the external flow field when the zero-mass jet works in a single mode.

[0042] The second and third zero-mass jet actuator outlets 1, 9 arranged on the inner side walls of the two inner flow paths 2 of the oscillating jet actuator should be as close as possible to the controlled pneumatic profile wall 8.

[0043] In practical applications, the above-mentioned multi-modal wide-adaptability active flow control actuator is arranged in multiple positions on the pneumatic surface. Each active flow control actuator is connected to the air source supply pipeline 13 through a branch pipeline. A sub-valve is set on each branch pipeline 15, and a main valve 14 is set on the air supply pipeline 13.

[0044] The air supply sub-valve (first sub-valve 12, second sub-valve 16, etc.) of a single active flow control actuator and the main valve 14 of the air supply pipeline are arranged on the air supply pipeline. By controlling the closing of the valve and the air pressure value, the different mode working functions of the combined actuator are controlled. The specific control method is as follows:

[0045] ① When the air supply sub-valves of each active flow control actuator are closed, each active flow control actuator is in a state of working alone. At this time, the zero-mass jet actuator is started, which is a single zero-mass jet actuator working mode.

[0046] ② When the air supply sub-valves and the main valve of the air supply pipeline of each active flow control actuator are open, and the zero-mass jet actuator is not started, if the main valve of the air supply pipeline is under high pressure conditions, it is the oscillating jet flow control single working mode; if the main valve of the air supply pipeline is under low pressure conditions, it is the micro-suction flow control single working mode;

[0047] When the air supply sub-valves and the air supply pipeline main valve of each active flow control actuator are opened and the zero-mass jet actuator is started, if the air supply pipeline main valve is under high-pressure conditions, it is a combined mode in which the oscillation jet flow control and the zero-mass jet actuator work together; if the air supply pipeline main valve is under low-pressure conditions, it is a combined mode in which the micro-suction flow control and the zero-mass jet actuator work together.

[0048] ③ When the air supply sub-valves of each active flow control actuator are opened and the main valve of the air supply pipeline is closed, it is the working mode of the combination of the related actuators. The local pressure difference at the outlets of different positions where each of them is arranged can be combined to realize the flow direction and specific control of the airflow between the branches. For example, the high-pressure area near the stagnation point of the leading edge of the wing is used to bleed air to provide a certain quality of high-pressure airflow for the air supply pipelines of actuators in other areas.

[0049] The active flow control method of this embodiment organically combines the three existing active flow modes of zero-mass synthetic jet, oscillating jet and micro-suction, and makes full use of their respective advantages by taking advantage of their strengths and making up for their weaknesses, so that the combined flow control actuator system has multiple modes, which can work independently according to different flight conditions or in combination with each other.

[0050] In the above embodiment, if Figure 3 As shown, when the flow control system is in a single-mode working state, the air supply valves (12, 16, etc.) of each actuator module are closed, and the zero-mass synthetic jet mode inside the actuator has the characteristics of low energy consumption when working alone, and is mainly used for flow separation control in the local area of ​​the surface during the cruise phase; when the oscillating jet mode works alone, it will maintain an efficient frequency-locked working state at the optimal design point; when the micro-suction mode works alone, it can control and delay the laminar transition of the aerodynamic shape surface and reduce friction.

[0051] When the flow control system is working in the combined mode, the zero-mass synthetic jet and oscillating jet control are combined. The zero-mass synthetic jet can be used to drive the oscillating jet to achieve wide-frequency frequency conversion and adjust the jet speed control, thereby obtaining the flight envelope flow control capability in a wide speed range and large airspace. The oscillating jet and micro-suction modes are combined, and at the same time, combined with air bleed from high-pressure areas such as the leading edge stagnation point, the airflow working fluid in the multi-modal actuator module pipeline connected to it can be recycled and optimized, thereby improving the input energy utilization efficiency and output energy bandwidth of active flow control.

[0052] Features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or used in place of features in other embodiments.

[0053] It should be emphasized that the term "include / comprises" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0054] The many features and advantages of these embodiments are apparent from this detailed description, and thus the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended that the embodiments of the invention be limited to the exact construction and operation illustrated and described, but rather all suitable modifications and equivalents falling within the scope thereof are intended to be covered.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0056] Parts of the present invention that are not described in detail are well known to those skilled in the art.

Claims

1. A multi-modal wide adaptability active flow control actuator, characterized in that: It includes an oscillating jet exciter and a zero-mass jet exciter, wherein the zero-mass jet exciter is arranged between two inner flow paths of the oscillating jet exciter; an opening is respectively arranged at the splitting position of the two inner flow paths of the oscillating jet exciter and on the inner walls on both sides, which are connected to the outlet of the zero-mass jet exciter; an air supply inlet and two control ports are arranged at the top of the oscillating jet exciter, the air supply inlet is connected to the air source through the air supply pipeline, the air supply pipeline is provided with a main valve, and the main valve controls the air source to provide high-pressure or low-pressure gas; an outlet is respectively arranged at the bottom of the two inner flow paths, which are connected to the outside of the controlled pneumatic surface wall.

2. The multi-modal wide adaptability active flow control actuator according to claim 1, characterized in that: The massless jet exciter is three small exciters, and the outlets correspond to the opening positions; or the massless jet exciter is one large exciter, and has three outlets corresponding to the opening positions.

3. The multi-modal wide adaptability active flow control actuator according to claim 1, characterized in that: The control port is located outside the main side wall of the oscillating jet actuator and is used to control the basic operating frequency of the oscillating jet.

4. The multi-modal wide adaptability active flow control actuator according to claim 1, characterized in that: The active flow control actuator is embedded on the wall surface of the controlled pneumatic profile by a direct built-in embedding method.

5. The multi-modal wide adaptability active flow control actuator according to claim 1, characterized in that: The active flow control actuators are multiple and arranged at different positions on the pneumatic surface. Each active flow control actuator is connected to the air source supply pipeline through a branch pipeline, and a sub-valve is also arranged on each branch pipeline.

6. A multi-modal wide adaptability active flow control actuator control method, characterized in that: The multi-modal wide-adaptability active flow control actuator according to any one of claims 1 to 4 is adopted, and the specific control method is as follows: The main valve is closed, the zero-mass jet actuator is started, and the zero-mass jet actuator works alone; The main valve is opened, the zero-mass jet actuator is not started, and the main valve of the air supply pipeline is controlled to be in high-pressure condition, which is the single working mode of oscillating jet flow control; The main valve is opened, the zero-mass jet actuator is not started, and the main valve of the air supply pipeline is controlled to be in a low-pressure condition, which is a separate working mode for micro-suction flow control; The main valve is opened, the zero-mass jet actuator is started, and the main valve of the air supply pipeline is controlled to be under high-pressure conditions, which is a combined working mode of oscillating jet flow control and zero-mass jet actuator; The main valve is opened, the zero-mass jet actuator is started, and the main valve of the air supply pipeline is controlled to be in a low-pressure condition, which is a combined working mode of micro-suction flow control and zero-mass jet actuator; Select the appropriate working mode according to different flight conditions.

7. The multi-modal wide adaptability active flow control actuator control method according to claim 6, characterized in that: At least two active flow control actuators are used and arranged at different positions on the pneumatic surface. Each active flow control actuator is connected to the air source supply pipeline through a branch pipeline. A sub-valve is set on each branch pipeline to control the main valve to close and the sub-valve to open. Airflow is formed between multiple active flow control actuators due to the local pressure difference to control the working mode.

8. The multi-modal wide adaptability active flow control actuator control method according to claim 7, characterized in that: At least one active flow control actuator is arranged at the leading edge of the wing.

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