A method of designing a vertical tail spoiler strip

Abstract

The application belongs to the field of aircraft structure design, and particularly relates to a vertical tail spoiler design method. The method comprises the following steps: step one, obtaining a vertical tail configuration without a spoiler, performing flow field analysis on the vertical tail configuration without the spoiler to obtain a first flow field analysis result; step two, obtaining a vertical tail configuration without a spoiler gap, performing flow field analysis on the vertical tail configuration without the spoiler gap to obtain a second flow field analysis result; step three, obtaining a vertical tail configuration with a spoiler gap, performing flow field analysis on the vertical tail configuration with the spoiler gap to obtain a third flow field analysis result; step four, improving the configuration according to the first flow field analysis result, the second flow field analysis result and the third flow field analysis result to obtain an improved vertical tail configuration with the spoiler; and step five, performing flow field analysis on the improved vertical tail configuration with the spoiler to obtain a fourth flow field analysis result, and determining whether the improved vertical tail configuration with the spoiler meets design requirements according to the fourth flow field analysis result.

Description

Technical Field

[0001] This application belongs to the field of aircraft structural design, and specifically relates to a design method for a vertical tail spoiler. Background Technology

[0002] Spoilers clearly distinguish the functions of the stabilizer and rudder from an aerodynamic perspective. The stabilizer is responsible for the overall directional stability of the aircraft, while the rudder is only used to adjust the aircraft's flight direction. After installing spoilers, the position of the shock wave of the local supersonic airflow is fixed at the side edge of the spoiler, so the pressure center position of the vertical tail and the overall directional moment characteristics of the aircraft will not change significantly. Adding spoilers to the vertical tail provides an inwardly deflected plane—a concave surface—for the shock wave generated by the local supersonic airflow. After passing through the oblique shock wave, the airflow is pressurized and decelerated, flowing at a low speed past the rudder, thus solving the transonic vibration problem.

[0003] However, while the spoiler strips solve the problem of vertical tail vibration reduction, they also have adverse effects on the vertical tail flow field. On the one hand, they reduce the load on the vertical tail stabilizer, which means they reduce the yaw moment characteristics of the vertical tail and reduce the stability of the vertical tail. On the other hand, they increase the useless load on the rudder and reduce the rudder's control efficiency.

[0004] Therefore, it is desirable to have a technical solution to overcome or at least mitigate one of the aforementioned defects of the prior art. Summary of the Invention

[0005] The purpose of this application is to provide a design method for a vertical tail spoiler to solve at least one problem existing in the prior art.

[0006] The technical solution of this application is:

[0007] A method for designing a vertical tail spoiler includes:

[0008] Step 1: Obtain the unperturbed flow stripe vertical tail configuration, perform flow field analysis on the unperturbed flow stripe vertical tail configuration, and obtain the first flow field analysis result;

[0009] Step 2: Obtain the configuration of the vertical tail without notches of the spoiler strip, and perform flow field analysis on the configuration of the vertical tail without notches of the spoiler strip to obtain the second flow field analysis result;

[0010] Step 3: Obtain the configuration of the spoiler strip with notched vertical tail, and perform flow field analysis on the configuration of the spoiler strip with notched vertical tail to obtain the third flow field analysis result;

[0011] Step 4: Based on the first flow field analysis results, the second flow field analysis results, and the third flow field analysis results, the configuration is improved to obtain the improved vertical tail configuration with turbulence strips;

[0012] Step 5: Perform flow field analysis on the improved vertical tail configuration of the spoiler strip to obtain the fourth flow field analysis result. Based on the fourth flow field analysis result, determine whether the improved vertical tail configuration of the spoiler strip meets the design requirements.

[0013] In at least one embodiment of this application, CFL3D software is used for flow field analysis.

[0014] In at least one embodiment of this application, in step one, when performing flow field analysis on the unperturbed flow stripe vertical tail configuration, the following flow field data of the unperturbed flow stripe vertical tail configuration are analyzed:

[0015] Surface streamlines and pressure distribution contour maps of the vertical tail at different Mach numbers;

[0016] Mach number distribution contour maps of vertical tail profiles at different Mach numbers;

[0017] Comparison of pressure distribution in the profile of the vertical tail at different Mach numbers.

[0018] In at least one embodiment of this application, in step one, the first flow field analysis result includes:

[0019] The streamlines on the vertical tail are downstream attachment flows;

[0020] As the Mach number increases, shock waves begin to be generated on the vertical tail, and the position of the shock waves moves from front to back until the trailing edge of the vertical tail.

[0021] As the Mach number increases, the center of gravity of the vertical stabilizer moves from front to back, and the yaw moment characteristics of the aircraft also increase.

[0022] In at least one embodiment of this application, step two, obtaining the notch-less vertical tail configuration of the spoiler strip, includes:

[0023] The entire spoiler is arranged at the junction of the stabilizer and the rudder of the vertical tail, resulting in a vertical tail configuration with no gaps in the spoiler.

[0024] In at least one embodiment of this application, in step two, when performing flow field analysis on the unnotched vertical tail configuration of the spoiler strip, the following flow field data of the unnotched vertical tail configuration of the spoiler strip are analyzed:

[0025] Streamlines and pressure distribution contours on the vertical tail surface.

[0026] In at least one embodiment of this application, in step two, the second flow field analysis result includes:

[0027] A low Mach region is generated near the spoiler, and a high Mach region is generated before and after the spoiler;

[0028] The airflow on the rudder all originates from the root of the rudder, and the high-speed airflow in front flows orderly upward along the rudder from the bottom of the spoiler strip.

[0029] In at least one embodiment of this application, step three, obtaining the notched vertical tail configuration of the spoiler strip, includes:

[0030] Multiple spoilers are arranged at the junction of the stabilizer and the rudder of the vertical tail, and a gap is formed between two adjacent spoilers, resulting in a vertical tail configuration with a gap in the spoilers.

[0031] In at least one embodiment of this application, in step three, when performing flow field analysis on the notched vertical tail configuration of the spoiler strip, the following flow field data of the notched vertical tail configuration of the spoiler strip are analyzed:

[0032] Surface streamlines and pressure distribution contour maps of the vertical tail at different Mach numbers;

[0033] Mach number distribution contour maps of vertical tail profiles at different Mach numbers;

[0034] Comparison of pressure distribution in the profile of the vertical tail at different Mach numbers.

[0035] In at least one embodiment of this application, in step three, the third flow field analysis result includes:

[0036] The high-speed downstream airflow from the opening intersects with the longitudinal airflow on the rudder, resulting in turbulence on the rudder.

[0037] The spoiler strips reduce the load distribution on the vertical stabilizer surface;

[0038] High-speed airflow flows upward from the root of the rudder, increasing the useless load on the rudder.

[0039] In at least one embodiment of this application, step four involves improving the configuration to obtain a spoiler-improved vertical tail configuration, including:

[0040] The entire spoiler is arranged at the junction of the stabilizer and the rudder of the vertical tail, reducing the height of the spoiler in both the vertical tail configuration without a notch and the vertical tail configuration with a notch.

[0041] In at least one embodiment of this application, in step five, when performing flow field analysis on the improved vertical tail configuration of the spoiler, the following flow field data of the improved vertical tail configuration of the spoiler are analyzed:

[0042] Surface streamlines and pressure distribution contour maps of the vertical tail at different Mach numbers;

[0043] Mach number distribution contour maps of vertical tail profiles at different Mach numbers;

[0044] Comparison of pressure distribution in the profile of the vertical tail at different Mach numbers.

[0045] In at least one embodiment of this application, in step five, the fourth flow field analysis result includes:

[0046] As the Mach number increases, shock waves are generated at the side edge of the turbulence strip, the pressure increases, the airflow slows down, and then flows over the rudder as a downstream adhering flow.

[0047] A suction peak appears at the leading edge of the rudder, and the high-speed airflow is depressurized when it passes through the shock wave.

[0048] In at least one embodiment of this application, the method further includes step six: performing flow field analysis and comparison on the un-turbulent strip vertical tail configuration, the turbulent strip with notch vertical tail configuration, and the turbulent strip improved vertical tail configuration, and verifying the turbulent strip improved vertical tail configuration.

[0049] In at least one embodiment of this application, step six involves comparing the flow field of the un-turbulent vertical tail configuration, the turbulent vertical tail configuration with notches, and the improved turbulent vertical tail configuration, and verifying the improved turbulent vertical tail configuration, including:

[0050] At different Mach numbers, the overall drag coefficients of the aircraft with the unspoiler-bar vertical tail configuration, the spoiler-bar vertical tail configuration with notches, and the spoiler-bar improved vertical tail configuration are compared, and the spoiler-bar improved vertical tail configuration is verified.

[0051] In at least one embodiment of this application, step six involves comparing the flow field of the un-turbulent vertical tail configuration, the turbulent vertical tail configuration with notches, and the improved turbulent vertical tail configuration, and verifying the improved turbulent vertical tail configuration, including:

[0052] At the same Mach number, the pressure distribution at different vertical tail profiles of the unspoiler-free vertical tail configuration, the spoiler-with-notch vertical tail configuration, and the improved spoiler-with-vertical-tail configuration is compared to verify the improved spoiler-with-vertical-tail configuration.

[0053] The invention has at least the following beneficial technical effects:

[0054] The vertical tail spoiler design method of this application adopts an integrated design for the improved spoiler, which avoids airflow separation on the rudder caused by strong airflow at the opening. By reducing the height of the spoiler, not only can the main load of the vertical tail be evenly distributed on the vertical tail stabilizing surface, but the shock wave position is also fixed on the vertical tail stabilizing surface. At the same time, the airflow on the rudder is all in the same direction, without separation or separation vortex. This not only improves the efficiency of the rudder and the aerodynamic characteristics of the vertical tail, but also reduces the control power of the actuators and reduces the overall drag of the aircraft. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the vertical tail of one embodiment of this application;

[0056] Figure 2 This is a schematic diagram of the existing spoiler arrangement position on the vertical tail in one embodiment of this application;

[0057] Figure 3 This is a schematic diagram of an existing spoiler according to one embodiment of this application;

[0058] Figure 4 This is a streamline and pressure distribution cloud map of the surface of the undisturbed vertical tail configuration with a Mach number of 0.78 to 1.05 according to one embodiment of this application.

[0059] Figure 5 This is a cloud map showing the Mach number distribution of the vertical tail profile with a Mach number of 0.78 to 0.95 in an embodiment of this application with an unbumped vertical tail configuration.

[0060] Figure 6 This is a comparison diagram of the pressure distribution of the vertical tail profile at Mach numbers of 0.78 to 1.05 for an embodiment of the present application with an unbumped vertical tail configuration.

[0061] Figure 7 This is a cloud map showing the streamlines and pressure distribution on the surface of the vertical tail at different Mach numbers for a vertical tail configuration without notches in one embodiment of this application.

[0062] Figure 8 This is a schematic diagram of a spoiler with a notched vertical tail configuration according to one embodiment of this application;

[0063] Figure 9 This application provides an embodiment of a spoiler strip with a notched vertical tail configuration, and a streamline and pressure distribution cloud map of the vertical tail surface at a Mach number of 0.78 to 0.95.

[0064] Figure 10 This is a Mach number distribution cloud map of the vertical tail profile with a notched vertical tail configuration according to one embodiment of the present application, showing the Mach number distribution of the vertical tail with a Mach number of 0.78 to 0.95.

[0065] Figure 11 This is a comparison diagram of the pressure distribution of the vertical tail profile at Mach numbers of 0.78 to 0.95 for a spoiler bar with a notch configuration according to one embodiment of this application.

[0066] Figure 12 This is a schematic diagram of an improved vertical tail configuration of a spoiler strip according to one embodiment of this application;

[0067] Figure 13 This is a flow line and pressure distribution cloud map of the vertical tail surface at Mach numbers of 0.78 to 0.95 according to one embodiment of the present application for an improved vertical tail configuration with a spoiler strip.

[0068] Figure 14This is a cloud map showing the Mach number distribution of the vertical tail profile at Mach numbers of 0.78 to 0.95 for an improved vertical tail configuration with a spoiler strip according to one embodiment of this application.

[0069] Figure 15 This is a comparison diagram of the pressure distribution of the vertical tail profile at Mach numbers of 0.78 to 0.95 for an improved vertical tail configuration with a spoiler strip according to one embodiment of this application.

[0070] Figure 16 This is a comparison chart of the overall drag coefficient as a function of Mach number for different configurations of one embodiment of this application;

[0071] Figure 17 This is a comparison diagram of the pressure distribution curves of the vertical tail section at Z=1.6 meters for different configurations of one embodiment of this application;

[0072] Figure 18 This is a comparison of the pressure distribution curves of the vertical tail section at Z=2.5 meters for different configurations of one embodiment of this application;

[0073] Figure 19 This is a comparison of the pressure distribution curves of the vertical tail section at Z=3.3 meters for different configurations of one embodiment of this application. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0075] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this application.

[0076] The following is in conjunction with the appendix Figures 1 to 19 This application will be described in further detail.

[0077] This application provides a method for designing a vertical tail spoiler, including the following process:

[0078] Step 1: Obtain the unperturbed stripe vertical tail configuration, perform flow field analysis on the unperturbed stripe vertical tail configuration, and obtain the first flow field analysis results;

[0079] Step 2: Obtain the configuration of the vertical tail without notches of the spoiler strips, and perform flow field analysis on the configuration of the vertical tail without notches of the spoiler strips to obtain the second flow field analysis results;

[0080] Step 3: Obtain the configuration of the spoiler with notched vertical tail, perform flow field analysis on the configuration of the spoiler with notched vertical tail, and obtain the third flow field analysis result;

[0081] Step 4: Based on the results of the first flow field analysis, the second flow field analysis, and the third flow field analysis, the configuration is improved to obtain the improved vertical tail configuration with spoilers.

[0082] Step 5: Perform flow field analysis on the improved vertical tail configuration of the spoiler to obtain the fourth flow field analysis results. Based on the fourth flow field analysis results, determine whether the improved vertical tail configuration of the spoiler meets the design requirements.

[0083] This application presents a design method for a vertical tail spoiler. Based on the CFL3D commercial software for solving the Navier-Stokes equations, it analyzes the changes in the flow field on the vertical tail before and after adding the spoiler, the shortcomings of the original spoiler, and the improvement design of the spoiler. The software uses multigrid technology, the turbulence model is the SA model, and the computational grid is a structured grid drawn using ICEM-CFD software.

[0084] The vertical tail spoiler design method of this application, such as Figure 1-3 As shown, the spoiler strips on the vertical tail are arranged at the junction of the stabilizer and the rudder, which can clearly distinguish the functions of the stabilizer and the rudder from an aerodynamic point of view.

[0085] First, in step one, the unperturbed stripe vertical tail configuration is obtained. When performing flow field analysis on the unperturbed stripe vertical tail configuration, the following flow field data of the unperturbed stripe vertical tail configuration are analyzed:

[0086] Surface streamlines and pressure distribution contour maps of the vertical tail at different Mach numbers;

[0087] Mach number distribution contour maps of vertical tail profiles at different Mach numbers;

[0088] Comparison of pressure distribution in the profile of the vertical tail at different Mach numbers.

[0089] In this embodiment, the first flow field analysis results include: the streamlines on the vertical tail are downstream attached flows;

[0090] As the Mach number increases, shock waves begin to be generated on the vertical tail, and the position of the shock waves moves from front to back until the trailing edge of the vertical tail.

[0091] As the Mach number increases, the center of gravity of the vertical stabilizer moves from front to back, and the yaw moment characteristics of the aircraft also increase.

[0092] like Figure 4-6 As shown, the calculation results without spoilers indicate that the streamlines on the vertical tail at all calculated Mach numbers are downstream attachment flows. At Mach numbers no greater than 0.85, no shock waves appear on the vertical tail. At Mach number 0.9, shock waves begin to form on the vertical tail, and as the Mach number increases, the shock wave position moves from front to back until it reaches the trailing edge of the vertical tail. The center of pressure of the vertical tail also moves accordingly backward, and the yaw moment characteristics of the aircraft also increase.

[0093] When the shock wave position changes on the rudder, the load magnitude and pressure center position on the left and right rudder surfaces are not equal due to the rudder being a moving surface and the unsteadiness of the flow field. If the pressure centers on the left and right sides of the rudder are near the rudder axis, or even one in front of the other, it may induce rudder vibration and flutter, resulting in a series of transonic aeroelastic problems, or even unbearable vibrations. When the shock wave moves to the trailing edge of the vertical tail, the pressure centers on the left and right sides of the rudder are far from the axis of rotation, and the normal forces on the two sides of the rudder are not much different, so no large vibrations will occur.

[0094] In the vertical tail spoiler design method of this application, step two, obtaining the vertical tail configuration without notches for the spoiler, includes:

[0095] The entire spoiler is arranged at the junction of the stabilizer and the rudder of the vertical tail, resulting in a vertical tail configuration with no gaps in the spoiler.

[0096] In this embodiment, in step two, when performing flow field analysis on the vertical tail configuration without notches in the spoiler strips, the following flow field data of the vertical tail configuration without notches in the spoiler strips are analyzed:

[0097] Streamlines and pressure distribution contours on the vertical tail surface.

[0098] The results of the second flow field analysis include:

[0099] A low Mach region is generated near the spoiler, and a high Mach region is generated before and after the spoiler;

[0100] The airflow on the rudder all originates from the root of the rudder, and the high-speed airflow in front flows orderly upward along the rudder from the bottom of the spoiler strip.

[0101] like Figure 7As shown, in order to understand the effect of the notch on the flow field on the rudder, the flow field characteristics on the rudder when the spoiler strip has no notch were first studied: because the inviscid airflow runs fast, it is blocked by the spoiler strip, the airflow slows down and accumulates, resulting in a low Mach region near the spoiler strip, while the regions before and after it are high Mach regions; the flow on the rudder all originates from the root of the rudder, and the high-speed airflow in front flows orderly upward along the rudder from the bottom of the spoiler strip.

[0102] Prandt proposed the concept of "healthy flow," suggesting that when designing aircraft, one should seek sound and healthy engineering solutions and avoid unreliable "sick" and "bad" flows.

[0103] In the vertical tail spoiler design method of this application, step three, obtaining the notched vertical tail configuration of the spoiler includes:

[0104] Multiple spoilers are arranged at the junction of the stabilizer and the rudder of the vertical tail, and a gap is formed between two adjacent spoilers, resulting in a vertical tail configuration with a gap in the spoilers.

[0105] In this embodiment, in step three, when performing flow field analysis on the configuration of the spoiler with a notched vertical tail, the following flow field data of the spoiler with a notched vertical tail are analyzed:

[0106] Surface streamlines and pressure distribution contour maps of the vertical tail at different Mach numbers;

[0107] Mach number distribution contour maps of vertical tail profiles at different Mach numbers;

[0108] Comparison of pressure distribution in the profile of the vertical tail at different Mach numbers.

[0109] The results of the third flow field analysis include:

[0110] The high-speed downstream airflow from the opening intersects with the longitudinal airflow on the rudder, resulting in turbulence on the rudder.

[0111] The spoiler strips reduce the load distribution on the vertical stabilizer surface;

[0112] High-speed airflow flows upward from the root of the rudder, increasing the useless load on the rudder.

[0113] like Figure 8-10 As shown, the calculation results indicate that after the spoiler strips are installed with notches, while solving the problem of vertical tail vibration reduction, they also bring adverse effects to the vertical tail flow field: 1) Because the high-speed airflow in the direction of the flow from the notch and the airflow along the spanwise direction on the rudder intersect, the flow on the rudder becomes turbulent; 2) The spoiler strips reduce the load distribution on the vertical stabilizer, reducing the directional stability of the aircraft; 3) The high-speed airflow in front flows upward from the root of the rudder, increasing the useless load on the rudder and reducing the control efficiency of the rudder.

[0114] The vertical tail spoiler design method in this application is based on a comprehensive comparative analysis of the results of the first, second, and third flow field analyses. Adopting the design concept of "healthy flow," it first ensures that the rudder has a downstream attached flow, and then examines whether the improved spoiler can intercept the shock wave location in the same way as the existing spoiler, thus solving the transonic vibration problem. The improved spoiler design adopts a holistic design approach: 1) filling the gap; 2) reducing the height of the existing spoiler.

[0115] In this embodiment, step four involves improving the configuration to obtain an improved vertical tail configuration with spoilers, such as... Figure 11 The following are included:

[0116] The entire spoiler is arranged at the junction of the stabilizer and the rudder of the vertical tail, reducing the height of the spoiler in both the vertical tail configuration without a notch and the vertical tail configuration with a notch.

[0117] In this embodiment, in step five, when performing flow field analysis on the improved vertical tail configuration of the spoiler, the following flow field data of the improved vertical tail configuration of the spoiler are analyzed:

[0118] Surface streamlines and pressure distribution contour maps of the vertical tail at different Mach numbers;

[0119] Mach number distribution contour maps of vertical tail profiles at different Mach numbers;

[0120] Comparison of pressure distribution in the profile of the vertical tail at different Mach numbers.

[0121] The results of the fourth flow field analysis include:

[0122] As the Mach number increases, shock waves are generated at the side edge of the turbulence strip, the pressure increases, the airflow slows down, and then flows over the rudder as a downstream adhering flow.

[0123] A suction peak appears at the leading edge of the rudder, and the high-speed airflow is depressurized when it passes through the shock wave.

[0124] like Figure 12-14 As shown in the calculation results, the shock wave is generated at the side edge of the new spoiler, the pressure increases, the airflow decelerates, and then flows over the rudder as a downstream attached flow; a suction peak appears at the leading edge of the rudder, a phenomenon that does not exist when there is no spoiler, indicating that the local supersonic airflow is successfully depressurized when passing through the shock wave.

[0125] Understandably, if the fourth flow field analysis results indicate that the improved vertical tail configuration of the spoiler does not meet the design requirements, the process can be repeated to further improve the spoiler and iterate until a spoiler-improved vertical tail configuration that meets the design requirements is obtained.

[0126] The vertical tail spoiler design method of this application also includes step six, which involves comparing the flow field of the vertical tail configuration without spoilers, the vertical tail configuration with a notch in the spoiler, and the improved vertical tail configuration of the spoiler, and verifying the improved vertical tail configuration of the spoiler.

[0127] In one embodiment of this application, step six involves comparing the flow field of the un-turbulent vertical tail configuration, the turbulent vertical tail configuration with notches, and the improved turbulent vertical tail configuration, and verifying the improved turbulent vertical tail configuration, including:

[0128] At different Mach numbers, the overall drag coefficients of the aircraft with and without spoilers, with notched spoilers, and with improved spoilers were compared, and the improved spoiler configuration was verified.

[0129] like Figure 15 As shown, the drag coefficient curves of the three configurations as a function of Mach number are represented by no, now, and new, respectively. The calculation results show that, compared with the original spoiler configuration, the improved spoiler configuration significantly reduces the overall drag of the aircraft; at Mach number 0.85, the drag is reduced by 19 counts.

[0130] In another embodiment of this application, step six involves comparing the flow field of the un-turbulent vertical tail configuration, the turbulent vertical tail configuration with notches, and the improved turbulent vertical tail configuration, and verifying the improved turbulent vertical tail configuration, including:

[0131] At the same Mach number, the pressure distribution at different vertical tail profiles of the vertical tail configurations without spoilers, with notched spoilers, and with improved spoilers is compared, and the improved spoiler configuration is verified.

[0132] When modern supersonic fighter jets fly at high Mach numbers, the efficiency of the vertical tail decreases significantly, and the directional stability of the aircraft decreases sharply. If the directional stability is too low at this time, the aircraft will experience divergent motion with gradually increasing sideslip angle when subjected to lateral disturbances (such as gusts, engine failure, etc.), which may result in difficulty in control or even loss of control.

[0133] like Figure 16-19 As shown, the curves corresponding to the three configurations are represented by "no," "now," and "new," respectively. The calculation results show that, regarding the pressure distribution curve on the vertical stabilizer, the curve for the improved spoiler is basically consistent with the curve for the aircraft without spoilers, indicating that the improved spoiler did not change the aircraft's directional moment characteristics. Conversely, the original spoiler, on the one hand, reduced the load on the vertical stabilizer, thus reducing the directional moment characteristics of the vertical stabilizer and lowering its stability; on the other hand, it increased the useless load on the rudder, reducing the rudder's control efficiency.

[0134] The vertical tail spoiler design method of this application adopts an integrated design for the improved spoiler, which avoids airflow separation on the rudder caused by strong airflow at the opening. By reducing the height of the spoiler, not only can the main load of the vertical tail be evenly distributed on the vertical tail stabilizing surface, but the shock wave position is also fixed on the vertical tail stabilizing surface. At the same time, the airflow on the rudder is all in the same direction, without separation or separation vortex. This not only improves the efficiency of the rudder and the aerodynamic characteristics of the vertical tail, but also reduces the control power of the actuators and reduces the overall drag of the aircraft.

[0135] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method of designing a vertical tail spoiler bar, characterized by, The application relates to a vertical tail configuration improvement method. Step one: obtaining a vertical tail configuration without a spoiler, performing flow field analysis on the vertical tail configuration without a spoiler to obtain a first flow field analysis result; Step two: obtaining a vertical tail configuration without a spoiler and with a spoiler, performing flow field analysis on the vertical tail configuration without a spoiler and with a spoiler to obtain a second flow field analysis result; Step three: obtaining a vertical tail configuration with a spoiler and with an opening, performing flow field analysis on the vertical tail configuration with a spoiler and with an opening to obtain a third flow field analysis result; Step four: improving the configuration according to the first flow field analysis result, the second flow field analysis result and the third flow field analysis result to obtain a vertical tail configuration with an improved spoiler; Step five: performing flow field analysis on the vertical tail configuration with an improved spoiler to obtain a fourth flow field analysis result, and judging whether the vertical tail configuration with an improved spoiler meets design requirements according to the fourth flow field analysis result. In step one, the first flow field analysis result comprises: The flow lines on the vertical tail are attached flow in the streamwise direction; With the increase of the Mach number, the shock wave on the vertical tail begins to generate, the position of the shock wave moves from front to back until the trailing edge of the vertical tail; With the increase of the Mach number, the position of the pressure center of the vertical tail moves from front to back, and the heading moment characteristic of the airplane is also increased; In step two, the second flow field analysis result comprises: A low-Mach region is generated near the spoiler, and high-Mach regions are generated before and after the spoiler; The airflow on the rudder is all originated from the root of the rudder, and the high-speed airflow from the bottom end of the spoiler flows orderly upwards along the rudder; In step three, the third flow field analysis result comprises: The high-speed airflow from the opening and the airflow along the spanwise direction on the rudder cross, leading to the generation of turbulence on the rudder; The spoiler reduces the load distribution on the vertical stabilizer; The high-speed airflow flows upwards from the root of the rudder, and the useless load on the rudder is increased; In step four, the vertical tail configuration with an improved spoiler is obtained by improving the configuration, and the improvement comprises: The spoiler is arranged at the connection between the stabilizer of the vertical tail and the rudder, the height of the spoiler of the vertical tail configuration without an opening and the vertical tail configuration with an opening is reduced, and the spoiler is arranged on the whole vertical tail. In step five, the fourth flow field analysis result comprises: With the increase of the Mach number, the shock wave is generated at the side edge of the spoiler, the pressure is increased, the airflow is decelerated, and then the airflow flows through the rudder in the attached flow in the streamwise direction; The suction peak appears at the leading edge of the rudder, and the high-speed airflow is released when passing through the shock wave.

2. The method of claim 1, wherein, The CFL3D software is adopted to perform flow field analysis.

3. The method of claim 2, wherein: In step one, the following flow field data of the vertical tail configuration without a spoiler is analyzed when performing flow field analysis on the vertical tail configuration without a spoiler: The flow line and pressure distribution cloud diagram of the vertical tail surface under different Mach numbers; The Mach number distribution cloud diagram of the vertical tail profile under different Mach numbers; The pressure distribution comparison diagram of the vertical tail profile under different Mach numbers.

4. The method of claim 3, wherein, In step two, the vertical tail configuration without a spoiler is obtained by arranging the whole spoiler at the connection between the stabilizer of the vertical tail and the rudder. In step two, the following flow field data of the vertical tail configuration without a spoiler is analyzed when performing flow field analysis on the vertical tail configuration without a spoiler:

5. The method of claim 4, wherein: The flow line and pressure distribution cloud diagram of the vertical tail surface. ​ 6. The method of claim 5, wherein: Step three, obtaining the notched vertical tail configuration of the spoiler strip includes: Multiple spoilers are arranged at the junction of the stabilizer and the rudder of the vertical tail, and a gap is formed between two adjacent spoilers, resulting in a vertical tail configuration with a gap in the spoilers.

7. The method of claim 6, wherein: In step three, when performing flow field analysis on the notched vertical tail configuration of the spoiler strip, the following flow field data of the notched vertical tail configuration of the spoiler strip are analyzed: Surface streamlines and pressure distribution contour maps of the vertical tail at different Mach numbers; Mach number distribution contour maps of vertical tail profiles at different Mach numbers; Comparison of pressure distribution in the profile of the vertical tail at different Mach numbers.

8. The method of claim 7, wherein: In step five, during the flow field analysis of the improved vertical tail configuration of the spoiler, the following flow field data of the improved vertical tail configuration of the spoiler are analyzed: Surface streamlines and pressure distribution contour maps of the vertical tail at different Mach numbers; Mach number distribution contour maps of vertical tail profiles at different Mach numbers; Comparison of pressure distribution in the profile of the vertical tail at different Mach numbers.

9. The method of claim 1, wherein, The process also includes step six, which involves performing flow field analysis and comparison on the un-turbulent strip vertical tail configuration, the turbulent strip with notch vertical tail configuration, and the turbulent strip improved vertical tail configuration, and verifying the turbulent strip improved vertical tail configuration.

10. The method of claim 9, wherein: Step six involves comparing the flow field of the un-turbulent vertical tail configuration, the turbulent vertical tail configuration with notches, and the improved turbulent vertical tail configuration, and verifying the improved turbulent vertical tail configuration, including: At different Mach numbers, the overall drag coefficients of the aircraft with the unspoiler-bar vertical tail configuration, the spoiler-bar vertical tail configuration with notches, and the spoiler-bar improved vertical tail configuration are compared, and the spoiler-bar improved vertical tail configuration is verified.

11. The method of designing a vertical tail spoiler bar according to claim 10, wherein, Step six involves comparing the flow field of the un-turbulent vertical tail configuration, the turbulent vertical tail configuration with notches, and the improved turbulent vertical tail configuration, and verifying the improved turbulent vertical tail configuration, including: At the same Mach number, the pressure distribution at different vertical tail profiles of the unspoiler-free vertical tail configuration, the spoiler-with-notch vertical tail configuration, and the improved spoiler-with-vertical-tail configuration is compared to verify the improved spoiler-with-vertical-tail configuration.

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