Flow control method based on intelligent model

Abstract

The invention provides a flow control method based on an intelligent model, and the method comprises the steps: carrying out the numerical simulation or wind tunnel test of the influence law of different flow control modes on the internal and external flow fields of an aircraft, and determining a layout scheme of a flow control system; acquiring internal and external flow fields of the aircraft, aerodynamic characteristics of the aircraft and performance data of an air inlet channel under different control variable conditions; establishing an incidence relation among wall surface typical point pressure, space flow field characteristics and air inlet performance parameters, and forming a flow intelligent control model; a flow field sensing system is formed; according to the flow intelligent control model and the flow field sensing system, inversion of flight internal and external space flow fields is carried out, and air inlet performance parameters are solved in real time; based on a flow intelligent control model and a flow field sensing system, a closed-loop intelligent control system for feed-forward and feedback control is constructed, and closed-loop flow intelligent control from intelligent sensing to intelligent decision-making to intelligent control is realized. According to the invention, the problem that the performance of the air inlet channel can only realize single-point optimization under the condition of no flow control is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft flow control, and in particular relates to a flow control method based on an intelligent model. Background Art

[0002] Wide-range forebody / inlet flow control is a bottleneck problem that affects the expansion of air-breathing high-speed aircraft from single-point cruise design to wide-range flight. Using the cruise Mach number as the design point will result in the problem of low Mach number inlet not starting, while using the low Mach number as the design point will bring about problems such as insufficient compression efficiency at high Mach numbers and Mach reflection caused by shock waves swallowing the inlet not starting. Wide-range aircraft have highly coupled internal and external flows, and the forebody / inlet has complex physical phenomena such as shock wave / shock wave, shock wave / boundary layer interference, boundary layer transition, and flow separation. Due to the wide range of Mach number changes in wide-range aircraft, shock wave / boundary layer interference changes dramatically with the flight environment. Typical shock wave boundary layer interference brings the following problems, such as shock wave buffeting during the aircraft's ascending acceleration / dive stage when the inlet does not start, and the large changes in shock wave interference characteristics during wide-range cruise flight can easily lead to performance deterioration, and the head and lip leading edge thermal environment is poor; for wide-range high-speed unmanned combat platforms, there is a problem of combined power mode conversion. During the mode conversion process, the high-speed and low-speed channel shock wave interference coupling is strong, which can easily lead to flow instability. Through flow control technology, the working range of the aircraft inlet can be widened, flow oscillation can be suppressed, and the thermal environment can be improved.

[0003] In the prior art, the commonly used flow control methods are mostly passive flow control or open-loop active flow control. Passive flow control is commonly used in aircraft as fixed suction holes to solve the problem of inlet failure due to flow separation at low Mach numbers. Although it can broaden the scope of use of the air inlet, it cannot improve the working performance of the air inlet in a wide range because it cannot adjust parameters such as the air inlet compression ratio according to the flight environment. The active flow control method can actively adjust the air inlet parameters to improve the air inlet performance at different flight speeds and altitudes; however, the active flow control method currently used in aircraft is open-loop control, that is, according to the predetermined flight profile, the air inlet is adjusted according to a predetermined procedure. When the flight profile is adjusted in real time or the atmospheric environment deviates from the standard state, the air inlet cannot be adaptively adjusted, resulting in performance degradation. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] The present invention provides a flow control method based on an intelligent model, the method comprising:

[0006] Conduct numerical simulation or wind tunnel tests on the effects of different flow control methods on the flow fields inside and outside the aircraft to determine the layout of the flow control system;

[0007] According to the determined flow control system layout plan, carry out numerical simulation or wind tunnel test of flow control mode to obtain the internal and external flow fields of the aircraft under different control variable conditions, as well as the aircraft aerodynamic characteristics and inlet performance data;

[0008] Based on the flow field data obtained under different control variable conditions, the correlation between the pressure at typical wall points, spatial flow field characteristics, and inlet performance parameters is established to obtain the key wall positions that are most sensitive to flow field characteristics and form a flow intelligent control model.

[0009] Pressure sensors are arranged at key wall positions with the highest sensitivity to flow field characteristics to form a flow field sensing system;

[0010] Inverse the flow field inside and outside the flight space based on the flow intelligent control model and the flow field sensing system, and solve the inlet performance parameters in real time;

[0011] Based on the flow intelligent control model and flow field perception system, a closed-loop intelligent control system with feedforward and feedback control is constructed to realize closed-loop flow intelligent control from intelligent perception to intelligent decision-making to intelligent control.

[0012] The technical solution of the present invention provides a flow control method based on an intelligent model. The method obtains the influence of different flow control methods on the internal and external flow fields of the aircraft through numerical simulation or wind tunnel test, and determines the layout plan of the flow control system; forms a flow intelligent control model by establishing the correlation between the pressure of typical points on the wall-the spatial flow field characteristics-the performance parameters of the inlet duct; inverts the spatial flow field inside and outside the flight according to the flow intelligent control model and the real-time pressure data of the key wall surface with the highest sensitivity to the flow field characteristics, and solves the inlet duct performance parameters in real time; forms a closed-loop intelligent control system of feedforward and feedback control based on the flow intelligent control model and the flow field sensing system. Compared with the prior art, the technical solution of the present invention solves the problem that the inlet duct performance can only achieve single-point optimization without flow control. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] 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.

[0014] Figure 1A flow control system layout scheme provided according to a specific embodiment of the present invention is shown;

[0015] Figure 2 A schematic diagram of a flow intelligent model control process provided according to a specific embodiment of the present invention is shown.

[0016] The above drawings include the following reference numerals:

[0017] 1. Aircraft front body; 2. Aircraft air inlet; 3. Suction control device; 4. Jet control device; 5. Deformable surface; 6. Deformation control mechanism; 7. Actuating mechanism. DETAILED DESCRIPTION

[0018] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0020] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values.

[0021] According to a specific embodiment of the present invention, a flow control method based on an intelligent model is provided, the method comprising:

[0022] Conduct numerical simulation or wind tunnel tests on the effects of different flow control methods on the flow fields inside and outside the aircraft to determine the layout of the flow control system;

[0023] According to the determined flow control system layout plan, carry out numerical simulation or wind tunnel test of flow control mode to obtain the internal and external flow fields of the aircraft under different control variable conditions, as well as the aircraft aerodynamic characteristics and inlet performance data;

[0024] Based on the flow field data obtained under different control variable conditions, the correlation between the pressure at typical wall points, spatial flow field characteristics, and inlet performance parameters is established to obtain the key wall positions that are most sensitive to flow field characteristics and form a flow intelligent control model.

[0025] Pressure sensors are arranged at key wall positions with the highest sensitivity to flow field characteristics to form a flow field sensing system;

[0026] Inverse the flow field inside and outside the flight space based on the flow intelligent control model and the flow field sensing system, and solve the inlet performance parameters in real time;

[0027] Based on the flow intelligent control model and flow field perception system, a closed-loop intelligent control system with feedforward and feedback control is constructed to realize closed-loop flow intelligent control from intelligent perception to intelligent decision-making to intelligent control.

[0028] By applying this configuration, a flow control method based on an intelligent model is provided. This method obtains the influence of different flow control methods on the internal and external flow fields of the aircraft through numerical simulation or wind tunnel test, and determines the layout plan of the flow control system; forms a flow intelligent control model by establishing the correlation between the pressure at typical points on the wall-the spatial flow field characteristics-the inlet performance parameters; inverts the flight internal and external spatial flow fields according to the flow intelligent control model and the real-time pressure data of the key wall with the highest sensitivity to the flow field characteristics, and solves the inlet performance parameters in real time; forms a closed-loop intelligent control system of feedforward and feedback control based on the flow intelligent control model and the flow field sensing system. The flow control method based on the intelligent model of the present invention can realize the intelligent control of the flow field, and realize that the inlet performance parameters are kept in the optimal state under different flight conditions. The technical solution of the present invention solves the problem that the inlet performance can only achieve single-point optimization without flow control.

[0029] Firstly, in the present invention, numerical simulation or wind tunnel test is carried out to study the influence of different flow control modes on the flow field inside and outside the aircraft, and the layout scheme of the flow control system is determined.

[0030] After the aircraft shape and internal flow channel profile are determined, numerical simulation or wind tunnel test of the influence of different flow control methods on the internal and external flow fields of the aircraft is first carried out. The main flow control methods include deformation control, suction control, jet control, etc. Through numerical simulation or wind tunnel test, the influence of different flow control methods on the internal and external flow fields of the aircraft is obtained, and the layout plan of the flow control system is determined, including the flow control method adopted, the layout position of the flow control device on the aircraft, etc. The flow control system can be composed of a single control method or multiple control methods.

[0031] Furthermore, in the present invention, after determining the flow control system layout plan, numerical simulation or wind tunnel test of the flow control method is carried out for the determined flow control system layout plan to obtain the internal and external flow fields of the aircraft under different control variable conditions, as well as the aircraft aerodynamic characteristics and inlet performance data.

[0032] Numerical simulation or wind tunnel test is carried out for the flow control mode to obtain the internal and external flow fields of the aircraft under different control variables, as well as the aerodynamic characteristics and inlet performance data of the aircraft. The control variables include the deformation of the forebody, the deformation of the throat, the suction flow, the forebody jet flow and the throat jet flow.

[0033] For a flow control layout scheme consisting of multiple control modes, it is also necessary to obtain the coupling interference data between different control modes.

[0034] Furthermore, in the present invention, after obtaining the internal and external flow fields of the aircraft under different control variable conditions, as well as the aerodynamic characteristics and inlet performance data of the aircraft, a correlation relationship between the pressure at typical wall points-spatial flow field characteristics-inlet performance parameters is established based on the flow field data obtained under different control variable conditions, and the key wall positions with the highest sensitivity to the flow field characteristics are obtained to form a flow intelligent control model.

[0035] Based on the flow field data obtained under different control variable conditions, typical flow features such as shock waves and separation bubbles are extracted, and machine learning methods such as graph convolution are used to reduce the dimension of the flow field, establish the correlation between the pressure at typical points on the wall, the spatial flow field characteristics, and the performance parameters of the inlet, and form a flow intelligent control model. At the same time, the correlation between the pressure at typical points on the wall and the spatial flow field characteristics is analyzed to obtain the key wall position with the highest sensitivity to the flow field characteristics.

[0036] Furthermore, in the present invention, pressure sensors are arranged at key wall positions with the highest sensitivity to flow field characteristics to form a flow field sensing system; the flow field in the flight internal and external spaces is inverted based on the flow intelligent control model and the flow field sensing system, and the inlet performance parameters are solved in real time.

[0037] Pressure sensors are placed at key wall locations that are most sensitive to flow field characteristics to form a flow field sensing system, which can obtain real-time pressure data of key locations during flight. Based on the flow intelligent control model and real-time pressure data, the flow field inside and outside the flight space is inverted, and the inlet performance parameters, including the total pressure recovery coefficient, compression ratio, and throat Mach number, are calculated in real time.

[0038] Furthermore, in the present invention, based on the flow intelligent control model and the flow field sensing system, a closed-loop intelligent control system of feedforward and feedback control is constructed to realize closed-loop flow intelligent control from intelligent perception to intelligent decision-making to intelligent control.

[0039] Based on the flow intelligent control model and flow field sensing system, a closed-loop intelligent control system of feedforward and feedback control is formed and implemented through controller hardware. The control actuator is designed to realize closed-loop flow intelligent control from intelligent perception to intelligent decision-making to intelligent control.

[0040] The flow control method based on the intelligent model of the present invention forms a rich flow field database by studying the mechanism and law of complex shock wave interference flow in wide-range aircraft internal and external flows, and establishes a shock wave interference flow field structure and flow control parameter (or geometry) relationship model based on the inversion of the relationship between the flight state, the controlled flow field and the active flow control based on machine deep learning. According to the changes in the flight environment of the aircraft, based on the sensor sensing flow field characteristics, the flow control model of machine deep learning is used to make intelligent decisions, trigger the active flow control device in real time, realize the flow field structure control of key parts, and make the aircraft performance in the optimal state.

[0041] Compared with the prior art, the flow control method based on the intelligent model of the present invention has the following beneficial effects:

[0042] First, the intelligent model can be combined with real-time data measured by sensors to invert the spatial flow field around the aircraft and perceive the flight environment in real time.

[0043] The second is to achieve real-time adjustment of the air inlet according to the flight environment through an intelligent model to ensure excellent air inlet performance over a wide speed range.

[0044] The third is to integrate flow control methods such as inlet deformation, suction, and jet, and establish an efficient comprehensive control method through an intelligent model.

[0045] In order to further understand the present invention, the following Figure 1 and Figure 2 The flow control method based on the intelligent model of the present invention is described in detail.

[0046] After the aircraft shape and internal flow channel profile are determined, numerical simulation or wind tunnel test of the influence of different flow control methods on the internal and external flow fields of the aircraft are carried out, such as Figure 1 As shown, a well-defined flow control system layout scheme is given.

[0047] In the figure, 1 is the aircraft front body, 2 is the aircraft air inlet, and the flow control system is mainly arranged at the aircraft front body / air inlet position; 5 is the deformable surface.

[0048] The suction control device 3 is mainly composed of a suction hole / suction slit located on the wall of the inlet duct, a suction cavity, and a corresponding actuating mechanism for controlling the opening and closing of the suction hole / suction slit. The function of the suction control device is to absorb the separation bubbles generated locally in the inlet duct when it deviates from the design state, so as to increase the capture flow and total pressure recovery coefficient of the inlet duct and expand the working range of the inlet duct.

[0049] The jet control device 4 is mainly composed of a jet nozzle located at the front body of the aircraft, a high-pressure air source, and a corresponding actuator mechanism for controlling the opening and closing of the jet nozzle and the jet flow rate. Through the lateral jet, the forebody flow field can be disturbed, and the forebody shock wave angle and position can be adjusted, thereby increasing the captured flow in the inlet duct and improving the wave system structure in the inlet duct.

[0050] The deformation control mechanism 6 changes the local profile of the forebody / inlet duct through a connecting rod. The deformation of the forebody profile is used to adjust the forebody shock wave position, and the deformation of the throat profile is used to adjust parameters such as the inlet duct compression ratio and the total pressure recovery coefficient, so that the inlet duct has good working performance within a wide speed range.

[0051] The actuating mechanism 7 is driven by a motor and is used for controlling the suction, jet and deformation devices.

[0052] like Figure 2 As shown, through numerical simulation or wind tunnel test, the correlation between control variables (forebody deformation, throat deformation, suction flow, forebody jet flow and throat jet flow, etc.) and flow field characteristics (separation bubble and shock wave position, etc.) and inlet performance parameters is obtained, and a flow intelligent control model is established.

[0053] Pressure sensors are arranged at key locations on the aircraft wall to form a flow sensing system.

[0054] The flow intelligent model, flow sensing system and flow control actuator together constitute the aircraft flow intelligent control system.

[0055] During the flight of the aircraft, as the flight Mach number, angle of attack, sideslip angle and other flight conditions change, the spatial flow field is inverted based on the real-time measured wall pressure data, and the key characteristic quantities of the flow field are extracted. The inlet performance parameters (such as compression ratio, total pressure recovery coefficient and flow coefficient, etc.) are used as control targets. According to the correlation established by the intelligent model, the control targets of the pressure distribution are mapped accordingly. The flow field is controlled by means of suction, jet, deformation, etc., so that the inlet performance parameters are kept in the optimal state under different flight conditions. The problem that the inlet performance can only achieve single-point optimality without flow control is solved.

[0056] In summary, the present invention provides a flow control method based on an intelligent model. The method obtains the influence of different flow control methods on the internal and external flow fields of the aircraft through numerical simulation or wind tunnel test, and determines the layout plan of the flow control system; forms a flow intelligent control model by establishing the correlation between the pressure at typical points on the wall-the spatial flow field characteristics-the inlet performance parameters; inverts the flight internal and external spatial flow fields according to the flow intelligent control model and the real-time pressure data of the key wall with the highest sensitivity to the flow field characteristics, and solves the inlet performance parameters in real time; forms a closed-loop intelligent control system of feedforward and feedback control based on the flow intelligent control model and the flow field sensing system. The flow control method based on the intelligent model of the present invention can realize the intelligent control of the flow field, and realize that the inlet performance parameters are kept in the optimal state under different flight conditions. The technical solution of the present invention solves the problem that the inlet performance can only achieve single-point optimality without flow control.

[0057] 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.

Claims

1. A flow control method based on an intelligent model, characterized in that: The flow control method based on the intelligent model includes: Conduct numerical simulation or wind tunnel tests on the effects of different flow control methods on the flow fields inside and outside the aircraft to determine the layout of the flow control system; According to the determined flow control system layout plan, carry out numerical simulation or wind tunnel test of flow control mode to obtain the internal and external flow fields of the aircraft under different control variable conditions, as well as the aircraft aerodynamic characteristics and inlet performance data; Based on the flow field data obtained under different control variable conditions, the correlation between the pressure at typical wall points, spatial flow field characteristics, and inlet performance parameters is established to obtain the key wall positions that are most sensitive to flow field characteristics and form a flow intelligent control model. Pressure sensors are arranged at key wall positions with the highest sensitivity to flow field characteristics to form a flow field sensing system; Inverse the flow field inside and outside the flight space based on the flow intelligent control model and the flow field sensing system, and solve the inlet performance parameters in real time; Based on the flow intelligent control model and flow field perception system, a closed-loop intelligent control system with feedforward and feedback control is constructed to realize closed-loop flow intelligent control from intelligent perception to intelligent decision-making to intelligent control.

2. The flow control method based on intelligent model according to claim 1, characterized in that: Flow control methods include deformation control, suction control or jet control.

3. The flow control method based on intelligent model according to claim 2, characterized in that: The flow control system layout plan includes the flow control method adopted and the layout position of the flow control device on the aircraft.

4. The flow control method based on intelligent model according to claim 3, characterized in that: In a determined flow control system layout scheme, the flow control mode is composed of a single control mode or a plurality of control modes.

5. The flow control method based on intelligent model according to claim 1, characterized in that: The controlled variables include the forebody deformation, throat deformation, suction flow, forebody jet flow and throat jet flow.

6. The flow control method based on intelligent model according to claim 4, characterized in that: For flow control layout schemes composed of multiple control methods, after obtaining the internal and external flow fields of the aircraft under different control variable conditions, as well as the aircraft aerodynamic characteristics and inlet performance data, it is also necessary to obtain the coupling interference data between different control methods.

7. The flow control method based on intelligent model according to claim 1, characterized in that: Based on the flow field data obtained under different control variable conditions, the typical flow characteristics of shock waves and separation bubbles are extracted, and the flow field is reduced in dimension using machine learning methods. The correlation between the pressure at typical points on the wall, the spatial flow field characteristics, and the inlet performance parameters is established to form a flow intelligent control model.

8. The flow control method based on intelligent model according to claim 7, characterized in that: By analyzing the correlation between the pressure at typical points on the wall and the spatial flow field characteristics, the key wall position with the highest sensitivity to the flow field characteristics is obtained.

9. The flow control method based on intelligent model according to claim 1, characterized in that: Inlet performance parameters include total pressure recovery coefficient, compression ratio and throat Mach number.

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