Design method of vertical fin spoiler

Abstract

The invention belongs to the field of aircraft structure design, and particularly relates to a vertical fin spoiler design method. Comprising the following steps: step 1, obtaining a non-spoiler vertical fin configuration, and carrying out flow field analysis on the non-spoiler vertical fin configuration to obtain a first flow field analysis result; step 2, obtaining a non-notch vertical fin configuration of the turbulent flow strip, and performing flow field analysis on the non-notch vertical fin configuration of the turbulent flow strip to obtain a second flow field analysis result; step 3, obtaining a notched vertical fin configuration of the turbulent flow strip, and performing flow field analysis on the notched vertical fin configuration of the turbulent flow strip to obtain a third flow field analysis result; 4, according to the first flow field analysis result, the second flow field analysis result and the third flow field analysis result, the configuration is improved, and a spoiler improved vertical fin configuration is obtained; and 5, carrying out flow field analysis on the spoiler strip improved vertical fin configuration to obtain a fourth flow field analysis result, and judging whether the spoiler strip improved vertical fin configuration meets the design requirements or not according to the fourth flow field analysis result.

Description

Technical Field

[0001] The present invention relates to the field of aircraft structure design, and in particular to a method for designing a vertical tail spoiler strip. Background Art

[0002] The spoiler strip can clearly distinguish the functions of the stabilizer and the rudder from the aerodynamic point of view. The stabilizer is responsible for the heading stability of the entire aircraft, while the rudder is only used to adjust the flight direction of the aircraft. After the spoiler strip is installed, the shock wave position of the local supersonic airflow is fixed at the side edge of the spoiler strip, so that the pressure center position of the vertical tail and the heading moment characteristics of the entire aircraft will not change significantly. Installing a spoiler strip on the vertical tail can provide an inward deflected plane - a concave angle surface - for the shock wave generated by the local supersonic flow. The airflow is pressurized and decelerated after passing through the oblique shock wave, and flows through the rudder at a low speed, solving the transonic vibration problem.

[0003] However, while the spoiler strip solves the problem of vertical tail vibration reduction, it also brings adverse effects to the vertical tail flow field. On the one hand, it reduces the load on the vertical tail stabilizer, that is, reduces the heading moment characteristics of the vertical tail and reduces the stability of the vertical tail; on the other hand, it increases the useless load on the rudder and reduces the rudder's control efficiency.

[0004] Therefore, it is desired to have a technical solution to overcome or at least alleviate at least one of the above-mentioned defects of the prior art. Summary of the invention

[0005] The purpose of the present application is to provide a method for designing a vertical tail spoiler strip 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 strip, comprising:

[0008] Step 1: obtaining a vertical tail configuration without spoiler strips, performing flow field analysis on the vertical tail configuration without spoiler strips, and obtaining a first flow field analysis result;

[0009] Step 2: obtaining a vertical tail configuration with no notch in the spoiler strip, and performing flow field analysis on the vertical tail configuration with no notch in the spoiler strip to obtain a second flow field analysis result;

[0010] Step 3, obtaining a spoiler strip having a notch vertical tail configuration, performing a flow field analysis on the spoiler strip having a notch vertical tail configuration, and obtaining a third flow field analysis result;

[0011] Step 4: 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 spoiler strip improved vertical tail configuration;

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

[0013] In at least one embodiment of the present application, CFL3D software is used to perform flow field analysis.

[0014] In at least one embodiment of the present application, in step 1, when performing flow field analysis on the vertical tail configuration without spoiler strips, the following flow field data of the vertical tail configuration without spoiler strips are analyzed:

[0015] Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers;

[0016] Mach number distribution cloud diagram of the vertical tail section at different Mach numbers;

[0017] Comparison of pressure distribution of vertical tail section at different Mach numbers.

[0018] In at least one embodiment of the present application, in step 1, the first flow field analysis result includes:

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

[0020] As the Mach number increases, shock waves begin to form on the vertical tail, and the shock wave position moves from front to back until it reaches the trailing edge of the vertical tail;

[0021] As the Mach number increases, the center of pressure of the vertical tail moves from front to back, and the aircraft's heading moment characteristics also increase.

[0022] In at least one embodiment of the present application, in step 2, obtaining a spoiler strip without a notch vertical tail configuration includes:

[0023] The entire spoiler strip is arranged at the connection between the stabilizer surface of the vertical tail and the rudder, so as to obtain a vertical tail configuration without a notch in the spoiler strip.

[0024] In at least one embodiment of the present application, in step 2, when performing flow field analysis on the vertical tail configuration without a notch and a spoiler strip, the following flow field data of the vertical tail configuration without a notch and a spoiler strip are analyzed:

[0025] Vertical tail surface streamlines and pressure distribution cloud diagram.

[0026] In at least one embodiment of the present application, in step 2, the second flow field analysis result includes:

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

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

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

[0030] A plurality of spoiler strips are arranged at the connection between the stabilizer surface of the vertical tail and the rudder, and a gap is formed between two adjacent spoiler strips, thereby obtaining a vertical tail configuration with spoiler strips and gaps.

[0031] In at least one embodiment of the present application, in step 3, when performing flow field analysis on the vertical tail configuration with a notch on the spoiler strip, the following flow field data of the vertical tail configuration with a notch on the spoiler strip is analyzed:

[0032] Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers;

[0033] Mach number distribution cloud diagram of the vertical tail section at different Mach numbers;

[0034] Comparison of pressure distribution of vertical tail section at different Mach numbers.

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

[0036] The downstream high-speed airflow from the notch intersects with the airflow along the span on the rudder, causing turbulence on the rudder.

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

[0038] The 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 the present application, in step 4, the configuration is improved to obtain a spoiler strip improved vertical tail configuration, including:

[0040] The entire spoiler strip is arranged at the connection between the stabilizer surface of the vertical tail and the rudder, and the height of the spoiler strip in the vertical tail configuration without a notch and the spoiler strip in the vertical tail configuration with a notch is reduced.

[0041] In at least one embodiment of the present application, in step 5, when performing flow field analysis on the spoiler strip improved vertical tail configuration, the following flow field data of the spoiler strip improved vertical tail configuration are analyzed:

[0042] Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers;

[0043] Mach number distribution cloud diagram of the vertical tail section at different Mach numbers;

[0044] Comparison of pressure distribution of vertical tail section at different Mach numbers.

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

[0046] As the Mach number increases, shock waves are generated at the side edges of the spoiler strips, the pressure increases, the airflow slows down, and then flows through the rudder as a downstream attachment flow;

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

[0048] In at least one embodiment of the present application, the method further includes performing flow field analysis and comparison on the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips, and verifying the vertical tail configuration improved with spoiler strips.

[0049] In at least one embodiment of the present application, in step six, flow field analysis and comparison are performed on the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips, and the vertical tail configuration improved with spoiler strips is verified, including:

[0050] At different Mach numbers, the drag coefficients of the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips are compared, and the vertical tail configuration improved with spoiler strips is verified.

[0051] In at least one embodiment of the present application, in step six, flow field analysis and comparison are performed on the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips, and the vertical tail configuration improved with spoiler strips is verified, including:

[0052] At the same Mach number, the pressure distributions at different vertical tail sections of the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips are compared, and the vertical tail configuration improved with spoiler strips is verified.

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

[0054] The vertical tail spoiler strip design method of the present application adopts an integrated design for the improved spoiler strip, thereby avoiding the airflow separation on the rudder caused by the strong airflow at the notch; reducing the height of the spoiler strip can not only evenly distribute the main load of the vertical tail on the vertical tail stabilizer, but also fix the shock wave position on the vertical tail stabilizer, and at the same time, the airflow on the rudder is all in the downstream direction, and no separation and separation vortex appear, which not only improves the rudder efficiency and the aerodynamic characteristics of the vertical tail, reduces the control power of the actuator, but also reduces the resistance of the entire aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 is a schematic diagram of a vertical tail according to an embodiment of the present application;

[0056] Figure 2 It is a schematic diagram of the arrangement position of existing spoiler strips on a vertical tail according to an embodiment of the present application;

[0057] Figure 3 is a schematic diagram of an existing spoiler strip according to an embodiment of the present application;

[0058] Figure 4 It is a vertical tail surface streamline and pressure distribution cloud diagram at Mach number 0.78 to 1.05 of a vertical tail configuration without spoiler strips according to one embodiment of the present application;

[0059] Figure 5 It is a Mach number distribution cloud diagram of a vertical tail section at a Mach number of 0.78 to 0.95 for a vertical tail configuration without spoiler strips according to an embodiment of the present application;

[0060] Figure 6 This is a comparison diagram of the pressure distribution of the vertical tail section at Mach numbers of 0.78 to 1.05 for a vertical tail configuration without spoiler strips according to an embodiment of the present application;

[0061] Figure 7 It is a vertical tail surface streamline and pressure distribution cloud diagram at different Mach numbers of a vertical tail configuration with a spoiler strip without a notch according to an embodiment of the present application;

[0062] Figure 8 It is a schematic diagram of a spoiler strip with a notched vertical tail configuration according to an embodiment of the present application;

[0063] Fig. 9 It is a vertical tail surface streamline and pressure distribution cloud diagram at Mach number 0.78-0.95 of a vertical tail configuration with a spoiler strip having a notch according to one embodiment of the present application;

[0064] Fig.10 A Mach number distribution cloud diagram of a vertical tail section at a Mach number of 0.78 to 0.95 for a vertical tail configuration with a spoiler strip having a notch according to an embodiment of the present application;

[0065] Fig.11 This is a comparison diagram of the pressure distribution of the vertical tail section at Mach numbers of 0.78 to 0.95 for a vertical tail configuration with a spoiler strip having a notch according to an embodiment of the present application;

[0066] Fig.12 Schematic diagram of a spoiler strip improved vertical tail configuration according to an embodiment of the present application;

[0067] Fig.13 It is a vertical tail surface streamline and pressure distribution cloud diagram at Mach number 0.78-0.95 of a vertical tail configuration with a spoiler strip improved according to one embodiment of the present application;

[0068] Fig.14It is a Mach number distribution cloud diagram of the vertical tail section at Mach numbers of 0.78 to 0.95 for a vertical tail configuration with a spoiler strip improved according to one embodiment of the present application;

[0069] Fig.15 This is a comparison diagram of the pressure distribution of the vertical tail section at Mach numbers of 0.78 to 0.95 for a vertical tail configuration improved by spoiler strips according to an embodiment of the present application;

[0070] Fig.16 This is a comparison diagram of the drag coefficient of the whole aircraft with different configurations and the Mach number of an embodiment of the present application;

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

[0072] Fig.18 This is a comparison diagram of pressure distribution curves of the vertical tail section at Z=2.5 meters for different configurations of an embodiment of the present application;

[0073] Fig.19 It is a comparison diagram of the pressure distribution curves of the vertical tail section at Z=3.3 meters for different configurations of an embodiment of the present application. DETAILED DESCRIPTION

[0074] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the embodiment of this application will be described in more detail below in conjunction with the drawings in the embodiment of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described embodiments are part of the embodiments of this application, not all of them. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain this application, and should not be construed as limitations on this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The embodiments of this application are described in detail below in conjunction with the drawings.

[0075] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the scope of protection of the present application.

[0076] The following is combined with Figures 1 to 19 This application is described in further detail.

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

[0078] Step 1: obtaining a vertical tail configuration without spoiler strips, performing flow field analysis on the vertical tail configuration without spoiler strips, and obtaining a first flow field analysis result;

[0079] Step 2: obtaining a vertical tail configuration with no notch in the spoiler strip, performing flow field analysis on the vertical tail configuration with no notch in the spoiler strip, and obtaining a second flow field analysis result;

[0080] Step 3, obtaining a vertical tail configuration with a spoiler strip having a notch, performing a flow field analysis on the vertical tail configuration with a spoiler strip having a notch, and obtaining a third flow field analysis result;

[0081] Step 4: According to the first flow field analysis result, the second flow field analysis result and the third flow field analysis result, the configuration is improved to obtain a spoiler strip improved vertical tail configuration;

[0082] Step 5: Perform flow field analysis on the spoiler strip improved vertical tail configuration to obtain a fourth flow field analysis result, and determine whether the spoiler strip improved vertical tail configuration meets the design requirements based on the fourth flow field analysis result.

[0083] The vertical tail spoiler strip design method of this application analyzes the change of the flow field on the vertical tail before and after the spoiler strip is added, the shortcomings of the spoiler strip before improvement, and the improved design research of the spoiler strip based on the CFL3D commercial software for solving the NS equation. The software uses multi-grid technology, the turbulence model uses the SA model, and the calculation grid uses the structural grid drawn by the ICEM-CFD software.

[0084] The vertical tail spoiler strip design method of the present application is as follows: Figure 1-3 As shown, the spoiler strip on the vertical tail is arranged at the connection between the stabilizer and the rudder, which can clearly distinguish the functions of the stabilizer and the rudder from the aerodynamic point of view.

[0085] First, in step 1, a vertical tail configuration without spoiler strips is obtained. When performing flow field analysis on the vertical tail configuration without spoiler strips, the following flow field data of the vertical tail configuration without spoiler strips are analyzed:

[0086] Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers;

[0087] Mach number distribution cloud diagram of the vertical tail section at different Mach numbers;

[0088] Comparison of pressure distribution of vertical tail section at different Mach numbers.

[0089] In this embodiment, the first flow field analysis result includes: the streamline on the vertical tail is an attached flow in the downstream direction;

[0090] As the Mach number increases, shock waves begin to form on the vertical tail, and the shock wave position moves from front to back until it reaches the trailing edge of the vertical tail;

[0091] As the Mach number increases, the center of pressure of the vertical tail moves from front to back, and the aircraft's heading moment characteristics also increase.

[0092] like Figure 4-6 As shown in the figure, the calculation results without spoiler strips show that the streamlines on the vertical tail at all calculated Mach numbers are downstream attached flows. When the Mach number is not greater than 0.85, no shock wave appears on the vertical tail. When the Mach number is 0.9, shock waves begin to appear on the vertical tail. 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 pressure center of the vertical tail also moves backward accordingly, and the heading moment characteristics of the aircraft are also increasing.

[0093] When the shock wave position changes on the rudder, the load size and pressure center position on the left and right rudder surfaces are not equal due to the rudder being an active surface and the non-steady nature of the flow field. If the pressure centers on the left and right sides of the rudder are near the rudder's rotation axis, or even one in front of the other, it may induce vibration and flutter of the rudder, causing 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 rotation axis, and the normal forces on the rudder surfaces on both sides are not much different, so no large vibrations will be generated.

[0094] In the vertical tail spoiler strip design method of the present application, in step 2, obtaining a vertical tail configuration without a notch of the spoiler strip includes:

[0095] The entire spoiler strip is arranged at the connection between the stabilizer surface of the vertical tail and the rudder, so as to obtain a vertical tail configuration without a notch in the spoiler strip.

[0096] In this embodiment, in step 2, when the flow field analysis is performed on the vertical tail configuration with spoiler strips and no notches, the following flow field data of the vertical tail configuration with spoiler strips and no notches is analyzed:

[0097] Vertical tail surface streamlines and pressure distribution cloud diagram.

[0098] Among them, the second flow field analysis results include:

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

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

[0101] like Figure 7As shown in the figure, in order to understand the influence of the notch on the flow field on the rudder, the flow field characteristics on the rudder when the spoiler strip has no notch are studied first: since the inviscid airflow runs fast, it is blocked by the spoiler strip, the airflow slows down and accumulates, resulting in a low Mach area near the spoiler strip, while the front and rear are high Mach areas; the flow on the rudder originates from the root of the rudder, and the high-speed airflow in front flows upward in an orderly manner from the bottom of the spoiler strip along the rudder.

[0102] Plantl proposed the concept of "healthy flow", which suggests that when designing an aircraft, one should look for sound and healthy engineering solutions and avoid "pathological" and "bad" flows that cannot be relied upon.

[0103] In the vertical tail spoiler strip design method of the present application, in step 3, obtaining a vertical tail configuration with a spoiler strip having a notch includes:

[0104] A plurality of spoiler strips are arranged at the connection between the stabilizer surface of the vertical tail and the rudder, and a gap is formed between two adjacent spoiler strips, thereby obtaining a vertical tail configuration with spoiler strips and gaps.

[0105] In this embodiment, in step 3, when performing flow field analysis on the vertical tail configuration with a spoiler strip having a notch, the following flow field data of the vertical tail configuration with a spoiler strip having a notch are analyzed:

[0106] Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers;

[0107] Mach number distribution cloud diagram of the vertical tail section at different Mach numbers;

[0108] Comparison of pressure distribution of vertical tail section at different Mach numbers.

[0109] Among them, the third flow field analysis results include:

[0110] The downstream high-speed airflow from the notch intersects with the airflow along the span on the rudder, causing turbulence on the rudder.

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

[0112] The 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 in the figure, the calculation results show that after the spoiler strip is installed with a notch, while solving the problem of vertical tail vibration reduction, it also brings adverse effects to the vertical tail flow field: 1) Since the downstream high-speed airflow from the notch and the airflow along the span of the rudder intersect, the flow on the rudder becomes turbulent; 2) The spoiler strip reduces the load distribution on the vertical stabilizer and reduces the aircraft's heading stability; 3) The high-speed airflow in front flows upward from the root of the rudder, the useless load on the rudder increases, and the control efficiency of the rudder is reduced.

[0114] The vertical tail spoiler design method of the present application is comprehensively compared and analyzed based on the first flow field analysis results, the second flow field analysis results and the third flow field analysis results. The design concept of "healthy flow" is adopted. First, it is ensured that there is a downstream attachment flow on the rudder, and then it is determined whether the improved spoiler can intercept the position of the shock wave like the existing spoiler, that is, solve the transonic vibration problem. The improved spoiler design adopts the concept of overall design: 1) to fill the gap; 2) to reduce the height of the existing spoiler.

[0115] In this embodiment, in step 4, the configuration is improved to obtain a spoiler strip improved vertical tail configuration, such as Fig.11 Shown include:

[0116] The entire spoiler strip is arranged at the connection between the stabilizer surface of the vertical tail and the rudder, and the height of the spoiler strip of the vertical tail configuration without a spoiler strip notch and the spoiler strip of the vertical tail configuration with a spoiler strip notch is reduced.

[0117] In this embodiment, in step 5, when performing flow field analysis on the spoiler strip improved vertical tail configuration, the following flow field data of the spoiler strip improved vertical tail configuration are analyzed:

[0118] Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers;

[0119] Mach number distribution cloud diagram of the vertical tail section at different Mach numbers;

[0120] Comparison of pressure distribution of vertical tail section at different Mach numbers.

[0121] Among them, the fourth flow field analysis results include:

[0122] As the Mach number increases, shock waves are generated at the side edges of the spoiler strips, the pressure increases, the airflow slows down, and then flows through the rudder as a downstream attachment flow;

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

[0124] like Figure 12-14 As shown in the figure, from the calculation results, it can be seen that a shock wave is generated at the side edge of the new spoiler strip, the pressure increases, the airflow decelerates, and then it flows through the rudder in the downstream attachment flow; a suction peak appears at the leading edge of the rudder, which is not the case when there is no spoiler strip, indicating that the local supersonic airflow is very successful in releasing pressure when passing through the shock wave.

[0125] It can be understood that if it is determined according to the fourth flow field analysis result that the spoiler strip-improved vertical tail configuration does not meet the design requirements, the step can be returned to further improve the spoiler strip and iteratively optimize until a spoiler strip-improved vertical tail configuration that meets the design requirements is obtained.

[0126] The vertical tail spoiler strip design method of the present application also includes step six, performing flow field analysis and comparison on a vertical tail configuration without a spoiler strip, a vertical tail configuration with a spoiler strip having a notch, and a vertical tail configuration improved with a spoiler strip, and verifying the vertical tail configuration improved with a spoiler strip.

[0127] In one embodiment of the present application, in step six, flow field analysis and comparison are performed on a vertical tail configuration without spoiler strips, a vertical tail configuration with notches in spoiler strips, and a vertical tail configuration improved with spoiler strips, and the vertical tail configuration improved with spoiler strips is verified, including:

[0128] At different Mach numbers, the drag coefficients of the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips are compared, and the vertical tail configuration improved with spoiler strips is verified.

[0129] like Fig.15 As shown in the figure, the three configurations of the whole aircraft drag coefficient change curve with Mach number are represented by no, now and new respectively. From the calculation results, compared with the spoiler strip configuration before the improvement, the improved spoiler strip configuration can significantly reduce the aircraft's whole aircraft drag. When the Mach number is 0.85, the whole aircraft drag is reduced by 19 counts.

[0130] In another embodiment of the present application, in step six, flow field analysis and comparison are performed on a vertical tail configuration without spoiler strips, a vertical tail configuration with spoiler strips and notches, and a vertical tail configuration improved with spoiler strips, and the vertical tail configuration improved with spoiler strips is verified, including:

[0131] At the same Mach number, the pressure distributions at different vertical tail sections of the vertical tail configurations, including the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips, are compared, and the vertical tail configuration improved with spoiler strips is verified.

[0132] When modern supersonic fighters fly at high Mach numbers, the efficiency of the vertical tail drops significantly, and the directional stability of the aircraft decreases sharply. If the directional stability is too small at this time, the aircraft will experience a divergent motion with a gradually increasing sideslip angle when it is subjected to lateral disturbances (such as gusts of wind, engine failure, etc.), which can make it difficult to control at best, or even out of control at worst.

[0133] like Figure 16-19 As shown, the curves corresponding to the three configurations are represented by no, now and new respectively. From the calculation results, in terms of the profile pressure distribution curve on the vertical stabilizer, the curve of the improved spoiler strip is basically consistent with the curve without the spoiler strip, indicating that the improved spoiler strip does not change the heading moment characteristics of the aircraft; on the contrary, the spoiler strip before the improvement, on the one hand, reduces the load on the vertical tail stabilizer, that is, reduces the heading moment characteristics of the vertical tail, reduces the stability of the vertical tail, and on the other hand, increases the useless load on the rudder, reducing the control efficiency of the rudder.

[0134] The vertical tail spoiler strip design method of the present application adopts an integrated design for the improved spoiler strip, thereby avoiding the airflow separation on the rudder caused by the strong airflow at the notch; reducing the height of the spoiler strip can not only evenly distribute the main load of the vertical tail on the vertical tail stabilizer, but also fix the shock wave position on the vertical tail stabilizer, and at the same time, the airflow on the rudder is all in the downstream direction, and no separation and separation vortex appear, which not only improves the rudder efficiency and the aerodynamic characteristics of the vertical tail, reduces the control power of the actuator, but also reduces the resistance of the entire aircraft.

[0135] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for designing a vertical tail spoiler strip, characterized in that: include: Step 1: obtaining a vertical tail configuration without spoiler strips, performing flow field analysis on the vertical tail configuration without spoiler strips, and obtaining a first flow field analysis result; Step 2: obtaining a vertical tail configuration with no notch in the spoiler strip, and performing flow field analysis on the vertical tail configuration with no notch in the spoiler strip to obtain a second flow field analysis result; Step 3, obtaining a spoiler strip having a notch vertical tail configuration, performing a flow field analysis on the spoiler strip having a notch vertical tail configuration, and obtaining a third flow field analysis result; Step 4: 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 spoiler strip improved vertical tail configuration; Step 5: Perform a flow field analysis on the spoiler strip improved vertical tail configuration to obtain a fourth flow field analysis result, and determine whether the spoiler strip improved vertical tail configuration meets the design requirements based on the fourth flow field analysis result.

2. The method for designing a vertical tail spoiler strip according to claim 1, characterized in that: CFL3D software was used for flow field analysis.

3. The method for designing a vertical tail spoiler strip according to claim 2, characterized in that: In step 1, when performing flow field analysis on the vertical tail configuration without spoiler strips, the following flow field data of the vertical tail configuration without spoiler strips are analyzed: Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers; Mach number distribution cloud diagram of the vertical tail section at different Mach numbers; Comparison of pressure distribution of vertical tail section at different Mach numbers.

4. The method for designing a vertical tail spoiler strip according to claim 3, characterized in that: In step 1, the first flow field analysis result includes: The streamlines on the vertical tail are downstream attached flows; As the Mach number increases, shock waves begin to form on the vertical tail, and the shock wave position moves from front to back until it reaches the trailing edge of the vertical tail; As the Mach number increases, the center of pressure of the vertical tail moves from front to back, and the aircraft's heading moment characteristics also increase.

5. The method for designing a vertical tail spoiler strip according to claim 4, characterized in that: In step 2, obtaining the spoiler strip without notch vertical tail configuration includes: The entire spoiler strip is arranged at the connection between the stabilizer surface of the vertical tail and the rudder, so as to obtain a vertical tail configuration without a notch in the spoiler strip.

6. The method for designing a vertical tail spoiler strip according to claim 5, characterized in that: In step 2, when performing flow field analysis on the vertical tail configuration with no notch and spoiler strip, the following flow field data of the vertical tail configuration with no notch and spoiler strip are analyzed: Vertical tail surface streamlines and pressure distribution cloud diagram.

7. The method for designing a vertical tail spoiler strip according to claim 6, characterized in that: In step 2, the second flow field analysis result includes: A low Mach area is generated near the spoiler strips, and a high Mach area is generated before and after the spoiler strips; The airflow on the rudder originates from the root of the rudder, and the high-speed airflow in front flows upward in an orderly manner along the rudder from the bottom of the spoiler strip.

8. The method for designing a vertical tail spoiler strip according to claim 7, characterized in that: In step 3, obtaining the spoiler strip having a notched vertical tail configuration includes: A plurality of spoiler strips are arranged at the connection between the stabilizer surface of the vertical tail and the rudder, and a gap is formed between two adjacent spoiler strips, thereby obtaining a vertical tail configuration with spoiler strips and gaps.

9. The method for designing a vertical tail spoiler strip according to claim 8, characterized in that: In step 3, when performing flow field analysis on the vertical tail configuration with a notch in the spoiler strip, the following flow field data of the vertical tail configuration with a notch in the spoiler strip are analyzed: Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers; Mach number distribution cloud diagram of the vertical tail section at different Mach numbers; Comparison of pressure distribution of vertical tail section at different Mach numbers.

10. The method for designing a vertical tail spoiler strip according to claim 9, characterized in that: In step three, the third flow field analysis result includes: The downstream high-speed airflow from the notch intersects with the airflow along the span on the rudder, causing turbulence on the rudder. The spoiler strips reduce the load distribution on the vertical stabilizer; The high-speed airflow flows upward from the root of the rudder, increasing the useless load on the rudder.

11. The method for designing a vertical tail spoiler strip according to claim 10, characterized in that: In step 4, the configuration is improved to obtain a spoiler strip improved vertical tail configuration, including: The entire spoiler strip is arranged at the connection between the stabilizer surface of the vertical tail and the rudder, and the height of the spoiler strip in the vertical tail configuration without a notch and the spoiler strip in the vertical tail configuration with a notch is reduced.

12. The method for designing a vertical tail spoiler strip according to claim 11, characterized in that: In step 5, when performing flow field analysis on the spoiler strip improved vertical tail configuration, the following flow field data of the spoiler strip improved vertical tail configuration are analyzed: Streamline and pressure distribution cloud diagram of the vertical tail surface at different Mach numbers; Mach number distribution cloud diagram of the vertical tail section at different Mach numbers; Comparison of pressure distribution of vertical tail section at different Mach numbers.

13. The method for designing a vertical tail spoiler strip according to claim 12, characterized in that: In step 5, the fourth flow field analysis result includes: As the Mach number increases, shock waves are generated at the side edges of the spoiler strips, the pressure increases, the airflow slows down, and then flows through the rudder as a downstream attachment flow; A suction peak appears at the leading edge of the rudder, and the high-speed airflow is released when passing through the shock wave.

14. The method for designing a vertical tail spoiler strip according to claim 1, characterized in that: The method further includes step six, performing flow field analysis and comparison on the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips, and verifying the vertical tail configuration improved with spoiler strips.

15. The method for designing a vertical tail spoiler strip according to claim 14, characterized in that: In step six, flow field analysis and comparison are performed on the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips, and the vertical tail configuration improved with spoiler strips is verified, including: At different Mach numbers, the drag coefficients of the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips are compared, and the vertical tail configuration improved with spoiler strips is verified.

16. The method for designing a vertical tail spoiler strip according to claim 15, characterized in that: In step six, flow field analysis and comparison are performed on the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips, and the vertical tail configuration improved with spoiler strips is verified, including: At the same Mach number, the pressure distributions at different vertical tail sections of the vertical tail configuration without spoiler strips, the vertical tail configuration with spoiler strips and notches, and the vertical tail configuration improved with spoiler strips are compared, and the vertical tail configuration improved with spoiler strips is verified.

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