A joint control wing design method for broadband shock wave buffeting

Abstract

The present invention discloses a joint control wing design method for broadband shock wave flutter, which belongs to the field of flow collaborative control, including: designing a swept wing geometric model, simulating and obtaining a flow field snapshot and response curve of the swept wing, processing by DMD dynamic mode decomposition, obtaining a first-order dominant mode structure cloud map, and determining the swept wing flutter type, control device and position parameter design method, and obtaining an updated swept wing geometric model; verifying according to the updated flutter type and the updated response curve, and completing the design of the swept wing. The present invention is based on DMD dynamic mode decomposition technology, obtains the flutter type by analyzing the flow field data of the swept wing, selects the corresponding control device and position parameter design method according to the flow characteristics of the wing, can suppress and eliminate the wing flutter in a targeted manner, reduce the difficulty of parameter optimization in wing design, and improve design efficiency.

Description

Technical Field

[0001] The present invention belongs to the field of flow cooperative control, and in particular relates to a joint control wing design method for broadband shock wave flutter. Background Art

[0002] In order to reduce wave drag and avoid severe stalling of the wing, most aircraft that need to fly at transonic speeds use swept wings, but more complex transonic flutter flows will occur on swept wings. In addition to the reciprocating motion similar to the two-dimensional problem on each flow section, the shock wave surface of the swept wing also presents the spanwise fluctuation phenomenon of the shock wave surface from the three-dimensional characteristics. Therefore, unlike the obvious peak of the transonic flutter spectrum of the two-dimensional airfoil, the transonic flutter of the three-dimensional swept wing will have certain broadband characteristics, and there are two instability modes in the chord direction and span direction. At this time, a single control device cannot simultaneously eliminate the broadband pulsating load phenomenon in different directions caused by the two instability modes of the three-dimensional transonic flutter. Therefore, it is necessary to design a joint control wing for the broadband multi-instability modes of transonic flow.

[0003] However, since there are too many parameters to be optimized in joint control, if the design of some control parameters can be guided by flow field characteristic analysis, the dimension of joint control parameter space can be reduced and the efficiency of control law design can be improved. The DMD (Dynamic Mode Decomposition) method, as a global stability analysis method of the flow field area, can characterize the development process of different flow structure modes in space along the flow direction, and has the potential to guide the position parameters and shape parameters of the control device. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present invention provides a method for designing a joint control wing for broadband shock wave flutter, which solves the problem of too many joint control parameters to be optimized and difficulty in designing a joint control wing for broadband multi-instability modes of transonic flow.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is: a joint control wing design method for broadband shock wave flutter, comprising the following steps:

[0006] S1: Design the swept wing geometry model and simulate the flow field snapshot and response curve of the swept wing;

[0007] S2: Based on the flow field snapshot of the swept wing, the DMD dynamic mode decomposition is used to process and obtain the first-order dominant mode structure cloud map;

[0008] S3: According to the first-order dominant mode structure cloud map, determine the swept wing buffet type, control device and position parameter design method, and update the swept wing to obtain an updated swept wing geometric model;

[0009] S4: obtaining an updated buffeting type and an updated response curve according to the updated swept wing geometric model;

[0010] S5: Based on the response curve in S1, the buffeting type in S3, the updated buffeting type and the updated response curve, the updated swept wing geometry model is verified to complete the design of the swept wing.

[0011] The beneficial effects of the present invention are as follows: based on the DMD dynamic modal decomposition technology, the present invention obtains the flutter type by analyzing the flow field data of the swept wing, and designs a corresponding control device and method, which can effectively suppress and eliminate wing flutter, reduce the difficulty of parameter optimization in wing design, improve design efficiency, and guide the control design of the wing through the dominant mode, accurately target the flow characteristics, and design a simple and efficient control strategy, which can significantly weaken the high-frequency components in the lift coefficient response of the wing, and enhance the performance and safety of the aircraft during transonic flight.

[0012] Further: the specific steps of S1 are as follows:

[0013] S101: Design the geometric shape and size of the swept wing and obtain the swept wing geometric model;

[0014] S102: Meshing the swept wing geometric model, and setting boundary conditions, physical models, and numerical algorithms for numerical simulation of the swept wing by configuring a numerical solver;

[0015] S103: According to the boundary conditions, physical model and numerical algorithm of the swept wing numerical simulation, a flow field snapshot and a response curve of the swept wing are obtained by simulation.

[0016] The beneficial effects of the above further scheme are as follows: the present invention designs a swept wing geometric model, performs meshing and configures a numerical solver, and provides a flow field snapshot and a response curve for subsequent modal analysis through simulation, thereby improving the efficiency and reliability of wing design optimization and reducing design costs and risks.

[0017] Further: the specific steps of S2 are as follows:

[0018] S201: constructing a flow field snapshot matrix and a mapping of the flow field snapshot matrix according to the flow field snapshot of the swept wing;

[0019] S202: According to the flow field matrix, a mathematical transformation is performed using DMD dynamic mode decomposition to obtain a unified flow field matrix;

[0020] S203: sorting the flow field matrices in a unified form according to the modal influence of the flow field matrices in a unified form, and selecting the flow field matrix corresponding to the largest modal influence to obtain a first-order dominant characteristic mode;

[0021] S204: According to the first-order dominant eigenmode, a first-order dominant modal structure cloud diagram corresponding to the first-order dominant eigenmode is obtained.

[0022] The beneficial effect of the above further scheme is: the present invention uses DMD dynamic mode decomposition to analyze the swept wing flow field snapshot, which can effectively identify the dominant vibration mode, improve the pertinence and effectiveness of the wing design, and facilitate the subsequent optimization design of the wing.

[0023] Further: the expressions of the flow field snapshot matrix and the mapping of the flow field snapshot matrix are as follows:

[0024]

[0025]

[0026]

[0027]

[0028] in, is the mapping of the flow field snapshot matrix, is the system matrix of the high-dimensional flow field, is a snapshot of the flow field of the swept wing, is the second flow field snapshot matrix, is the first flow field snapshot matrix, is the number of snapshots of the swept wing flow field, For the A snapshot of the swept wing flow field, For the A snapshot of the flow field on a swept wing.

[0029] The beneficial effects of the above further scheme are as follows: the present invention reduces the dimensionality of high-dimensional flow field data by constructing a snapshot matrix, which facilitates the processing and analysis of smooth data and retains the dynamic information in the flow field; through the mapping of the flow field snapshot matrix, it is convenient to process a large amount of flow field data and improve computing efficiency.

[0030] Further: the expression of the unified flow field matrix is ​​as follows:

[0031]

[0032] in, For the A snapshot of the swept wing flow field, Indicated in Time next The time coefficients of the normalized DMD dynamic mode decomposition modes, is the Frobenious norm normalized DMD modalities;

[0033] The expression of the modal influence is as follows:

[0034]

[0035] in, For the The influence of a mode in the entire sampling space is Indicated in Time next The time coefficients of the normalized DMD dynamic mode decomposition modes, is the number of snapshots of the swept wing flow field, For time, is the coordinate information of each grid point in the three-dimensional flow field, For the A snapshot of the flow field on a swept wing.

[0036] The beneficial effects of the above further scheme are: through the unified form of the flow field matrix, the first-order dominant mode that has the greatest impact on the flutter of the swept wing can be accurately identified, providing a basis for subsequent control design; through the first-order dominant mode structure cloud map, the spatial distribution of the dominant mode can be intuitively displayed, which is convenient for targeted wing design.

[0037] Further: the specific steps of S3 are as follows:

[0038] S301: Determine the flutter type of the swept wing according to the first-order dominant mode structure cloud diagram;

[0039] S302: Obtaining a control device corresponding to the flutter type according to the flutter type of the swept wing;

[0040] S303: According to the buffeting type and the control device, a corresponding position parameter design method is used to update the geometric model of the swept wing to obtain an updated geometric model of the swept wing.

[0041] The beneficial effect of the above further scheme is that the present invention adopts different control devices and position parameter design methods for different types of flutter, and can design the wing in a targeted manner to improve the aerodynamic performance and flight safety of the wing.

[0042] Further: the flutter types of the swept wing include: a first-order shock wave spanwise mode and a first-order shock wave chordwise mode;

[0043] The control device of the first-order shock wave spanwise mode is a passive bulge;

[0044] The control device of the first-order shock wave chord-wise mode is a trailing edge rudder surface;

[0045] The position parameter design method of the first-order shock wave spanwise mode is to set a passive bulge arranged along the chord direction at the midline position of each spanwise strip of the wing;

[0046] The method for designing the position parameters of the first-order shock wave chord-wise mode is to set a trailing edge control surface with a length similar to the shaking range at the wing tip of the wing.

[0047] The beneficial effect of the above further scheme is: after identifying the flutter type of the swept wing, the passive bulge, the trailing edge control surface and the corresponding position parameter design method are selected in a targeted manner, which can effectively suppress the flutter caused by the first-order shock wave spanwise mode and the first-order shock wave chordwise mode. The targeted wing design method of the present invention improves the accuracy and efficiency of the control measures and can optimize the aerodynamic performance and safety of the wing.

[0048] Further: the specific method of verification in S5 includes:

[0049] Determine whether the updated buffeting type is consistent with the buffeting type in S3. If so, the design of the swept wing is invalid, return to S1, and adjust the swept wing geometry model according to the first-order dominant mode structure cloud map in S2. Otherwise, complete the design of the swept wing.

[0050] Determine whether the lift coefficient in the response curve after the update is weakened compared with that in the response curve in S1. If so, complete the design of the swept wing. Otherwise, the design of the swept wing is invalid. Return to S1 and adjust the swept wing geometry model according to the first-order dominant mode structure cloud map in S2.

[0051] The beneficial effect of the above further scheme is: the present invention improves the efficiency of wing design by comparing the vibration types and response curves before and after the update, ensures the scientificity and effectiveness of the wing design, and improves the aerodynamic performance and flight safety of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A joint control wing design method for broadband shock wave flutter.

[0053] Figure 2 A comparison of the lift coefficient responses of the swept wing with and without a bulge. DETAILED DESCRIPTION

[0054] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0055] like Figure 1 As shown, a joint control wing design method for broadband shock wave flutter includes the following steps:

[0056] S1: Design the swept wing geometry model and simulate the flow field snapshot and response curve of the swept wing;

[0057] S2: Based on the flow field snapshot of the swept wing, the DMD dynamic mode decomposition is used to process and obtain the first-order dominant mode structure cloud map;

[0058] S3: According to the first-order dominant mode structure cloud map, determine the swept wing buffet type, control device and position parameter design method, and update the swept wing to obtain an updated swept wing geometric model;

[0059] S4: obtaining an updated buffeting type and an updated response curve according to the updated swept wing geometric model;

[0060] S5: Based on the response curve in S1, the buffeting type in S3, the updated buffeting type and the updated response curve, the updated swept wing geometry model is verified to complete the design of the swept wing.

[0061] In one embodiment of the present invention, the specific steps of S1 are as follows:

[0062] S101: Design the geometric shape and size of the swept wing and obtain the swept wing geometric model;

[0063] S102: Meshing the swept wing geometric model, and setting boundary conditions, physical models, and numerical algorithms for numerical simulation of the swept wing by configuring a numerical solver;

[0064] S103: According to the boundary conditions, physical model and numerical algorithm of the swept wing numerical simulation, a flow field snapshot and a response curve of the swept wing are obtained by simulation.

[0065] In one embodiment of the present invention, the specific steps of S2 are as follows:

[0066] S201: According to the flow field snapshot of the swept wing, the flow field snapshot matrix and the mapping of the flow field snapshot matrix are constructed, wherein, through the simulation of S1, The flow field snapshot at each moment can be written as The flow field snapshot sequence form at the moment is , among which The flow field snapshot at each moment is represented as a column vector , and the time interval between any two adjacent snapshots is , so, assuming that the flow field snapshot Flow field snapshot The linear mapping of is expressed as:

[0067]

[0068] in, is the system matrix of the high-dimensional flow field. If the dynamic system of the swept wing is nonlinear, the linear mapping process is the linear estimation process. According to the assumed linear mapping relationship, the system matrix Can reflect the dynamic characteristics of the system; The dimension of is very high, and it is necessary to calculate it from the data sequence through the method of order reduction. , which is convenient for subsequent DMD dynamic mode decomposition, according to 1 to The flow field snapshot at the time is used to establish two flow field snapshot matrices, whose expressions are as follows:

[0069]

[0070]

[0071] in, is the first flow field snapshot matrix, is the second flow field snapshot matrix, is the number of swept wing flow field snapshots; the mapping expression of the flow field snapshot matrix is ​​as follows:

[0072]

[0073] S202: According to the flow field matrix, a mathematical transformation is performed using DMD dynamic mode decomposition to obtain a unified flow field matrix. The expression of the unified flow field matrix is ​​as follows:

[0074]

[0075] in, For the A snapshot of the swept wing flow field, Indicated in Time next The time coefficients of the normalized DMD dynamic mode decomposition modes, is the Frobenious norm normalized DMD modalities;

[0076] S203: sorting the flow field matrices in a unified form according to the modal influence of the flow field matrices in a unified form, and selecting the flow field matrix corresponding to the largest modal influence to obtain a first-order dominant characteristic mode;

[0077] Among them, the expression of modal influence is as follows:

[0078]

[0079] in, For the The influence of a mode in the entire sampling space is Indicated in Time next The time coefficients of the normalized DMD dynamic mode decomposition modes, is the number of snapshots of the swept wing flow field, For time, is the coordinate information of each grid point in the three-dimensional flow field, For the A snapshot of the swept wing flow field; according to the modal influence , sort each mode, select the flow field matrix corresponding to the largest modal influence, and obtain the corresponding first-order dominant characteristic mode ;

[0080] S204: According to the first-order dominant characteristic mode, the first-order dominant mode structure cloud diagram corresponding to the first-order dominant characteristic mode is obtained, and the first-order dominant characteristic mode is Draw a three-dimensional graph and obtain the first-order dominant mode structure cloud diagram.

[0081] In one embodiment of the present invention, the specific steps of S3 are as follows:

[0082] S301: Determine the flutter type of the swept wing according to the first-order dominant mode structure cloud diagram;

[0083] Among them, the flutter types of the swept wing include: first-order shock wave span mode and first-order shock wave chord-wise mode; when the first-order dominant modal structure cloud diagram of the swept wing is dominated by the shock wave span effect, the flutter type of the swept wing is the first-order shock wave span mode, and when the first-order dominant modal structure cloud diagram of the swept wing is dominated by the shock wave chord-wise effect, the flutter type of the swept wing is the first-order shock wave chord-wise mode;

[0084] S302: Obtaining a control device corresponding to the flutter type according to the flutter type of the swept wing;

[0085] The control device of the first-order shock wave span mode is a passive bulge, which blocks the span flow of the wing to suppress and eliminate the shock wave span effect.

[0086] The control device of the first-order shock wave chord-wise mode is the trailing edge control surface, which suppresses the shock wave chord-wise effect by controlling the trailing edge control surface;

[0087] S303: updating the geometric model of the swept wing using a corresponding position parameter design method according to the buffeting type and the control device to obtain an updated geometric model of the swept wing;

[0088] Among them, the buffeting type is the first-order shock wave span mode, and the control device is a passive bulge. At this time, the spatial form of the swept wing is mainly presented as a spanwise staggered strip structure, reflecting the spanwise flow characteristics of the upper surface of the wing. The corresponding position parameter design method is to set a passive bulge arranged along the chord direction at the midline position of each spanwise strip of the wing to block the spanwise flow on the upper surface of the swept wing.

[0089] The buffeting type is the first-order shock wave chord-wise mode, and the control device is the trailing edge control surface. At this time, the spatial form of the swept wing is mainly presented as a chord-wise shaking structure at the wing tip. The corresponding position parameter design method is to set a trailing edge control surface with a length similar to the shaking range at the wing tip.

[0090] In one embodiment of the present invention, based on the updated swept-wing geometric model, an updated flutter type and an updated response curve can be obtained according to S1, S2 and S3.

[0091] In one embodiment of the present invention, the updated swept wing geometric model is verified according to the response curve in S1, the buffeting type in S3, the updated buffeting type and the updated response curve, and the design of the swept wing is completed; wherein the specific method of verification in S5 includes:

[0092] Determine whether the updated buffeting type is consistent with the buffeting type in S3. If so, the design of the swept wing is invalid, return to S1, and adjust the swept wing geometry model according to the first-order dominant mode structure cloud map in S2. Otherwise, complete the design of the swept wing; for example, if the dominant mode before control is the first-order shock wave span mode, and the dominant mode after control becomes the first-order shock wave chord mode, then the control design is considered to be effective;

[0093] Determine whether the updated response curve is consistent with the lift coefficient in the response curve in S1. If so, complete the design of the swept wing. Otherwise, the design of the swept wing is invalid. Return to S1 and adjust the swept wing geometry model according to the first-order dominant mode structure cloud map in S2. Figure 2As shown, it is a comparison diagram of the lift coefficient response of the swept wing with and without a bulge; it can be seen that the lift coefficient of the wing without a bulge has high-frequency changes, and vibrates multiple times from 0.3 seconds to 1.4 seconds. According to a joint control wing design method for broadband shock wave flutter according to the present invention, after bulge control is applied to the wing, the high-frequency component representing the spanwise effect of the shock wave in the lift coefficient response of the bulge wing is weakened, which illustrates the effectiveness of the bulge control.

[0094] The beneficial effects of the present invention are as follows: based on the DMD dynamic modal decomposition technology, the present invention obtains the flutter type by analyzing the flow field data of the swept wing, and designs a corresponding control device and method, which can effectively suppress and eliminate wing flutter, reduce the difficulty of parameter optimization in wing design, improve design efficiency, and guide the control design of the wing through the dominant mode, accurately target the flow characteristics, and design a simple and efficient control strategy, which can significantly weaken the high-frequency components in the lift coefficient response of the wing, and enhance the performance and safety of the aircraft during transonic flight.

Claims

1. A method for designing a joint control wing for broadband shock wave buffeting, characterized in that: The following steps are involved: S1: Design the swept wing geometry model and simulate the flow field snapshot and response curve of the swept wing; S2: Based on the flow field snapshot of the swept wing, the DMD dynamic mode decomposition is used to process and obtain the first-order dominant mode structure cloud map, which is as follows: S201: constructing a flow field snapshot matrix and a mapping of the flow field snapshot matrix according to the flow field snapshot of the swept wing; S202: According to the flow field matrix, a DMD dynamic mode decomposition is used to perform mathematical transformation to obtain a unified flow field matrix; S203: sorting the flow field matrices in a unified form according to the modal influence of the flow field matrices in a unified form, and selecting the flow field matrix corresponding to the largest modal influence to obtain a first-order dominant characteristic mode; S204: obtaining a first-order dominant mode structure cloud diagram corresponding to the first-order dominant mode according to the first-order dominant characteristic mode; S3: According to the first-order dominant mode structure cloud map, determine the swept wing buffet type, control device and position parameter design method, and update the swept wing to obtain an updated swept wing geometric model; S4: obtaining an updated buffeting type and an updated response curve according to the updated swept wing geometric model; S5: According to the response curve in S1, the buffeting type in S3, the updated buffeting type and the updated response curve, the updated swept wing geometric model is verified to complete the design of the swept wing; The expression of the unified flow field matrix is ​​as follows: in, For the A snapshot of the swept wing flow field, Indicated in Time next The time coefficients of the normalized DMD dynamic mode decomposition modes, is the Frobenious norm normalized DMD modalities; The expression of the modal influence is as follows: in, For the The influence of a mode in the entire sampling space is Indicated in Time next The time coefficients of the normalized DMD dynamic mode decomposition modes, is the number of snapshots of the swept wing flow field, For time, is the coordinate information of each grid point in the three-dimensional flow field, For the A snapshot of the flow field on a swept wing.

2. The method for designing a wing with joint control for broadband shock wave buffeting according to claim 1, characterized in that: The specific steps of S1 are as follows: S101: Design the geometric shape and size of the swept wing and obtain the swept wing geometric model; S102: Meshing the swept wing geometric model, and setting boundary conditions, physical models, and numerical algorithms for numerical simulation of the swept wing by configuring a numerical solver; S103: According to the boundary conditions, physical model and numerical algorithm of the swept wing numerical simulation, a flow field snapshot and a response curve of the swept wing are obtained by simulation.

3. The method for designing a wing with joint control for broadband shock wave buffeting according to claim 1, characterized in that: The expressions of the flow field snapshot matrix and the mapping of the flow field snapshot matrix are as follows: in, is the mapping of the flow field snapshot matrix, is the system matrix of the high-dimensional flow field, is a snapshot of the flow field of the swept wing, is the second flow field snapshot matrix, is the first flow field snapshot matrix, is the number of snapshots of the swept wing flow field, For the A snapshot of the swept wing flow field, For the A snapshot of the flow field on a swept wing.

4. The method for designing a wing with joint control for broadband shock wave buffeting according to claim 1, characterized in that: The specific steps of S3 are as follows: S301: Determine the flutter type of the swept wing according to the first-order dominant mode structure cloud diagram; The flutter types of the swept wing include: first-order shock wave spanwise mode and first-order shock wave chordwise mode; S302: Obtaining a control device corresponding to the flutter type according to the flutter type of the swept wing; The control device of the first-order shock wave spanwise mode is a passive bulge; The control device of the first-order shock wave chord-wise mode is a trailing edge rudder surface; S303: updating the geometric model of the swept wing using a corresponding position parameter design method according to the buffeting type and the control device to obtain an updated geometric model of the swept wing; The position parameter design method of the first-order shock wave spanwise mode is to set a passive bulge arranged along the chord direction at the midline position of each spanwise strip of the wing; The method for designing the position parameters of the first-order shock wave chord-wise mode is to set a trailing edge control surface with a length similar to the shaking range at the wing tip of the wing.

5. The method for designing a wing with joint control for broadband shock wave buffeting according to claim 1, characterized in that: The specific verification method in S5 includes: Determine whether the updated buffeting type is consistent with the buffeting type in S3. If so, the design of the swept wing is invalid, return to S1, and adjust the swept wing geometry model according to the first-order dominant mode structure cloud map in S2. Otherwise, complete the design of the swept wing. Determine whether the lift coefficient in the response curve after the update is weakened compared with that in the response curve in S1. If so, complete the design of the swept wing. Otherwise, the design of the swept wing is invalid. Return to S1 and adjust the swept wing geometry model according to the first-order dominant mode structure cloud map in S2.

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