A method for testing a capture trajectory of a biplane

Abstract

The application discloses a kind of double-body aircraft's capture trajectory wind tunnel test method, the purpose is to establish simulation in wind tunnel launch weapon from double-body aircraft separation capture trajectory test capability, belong to wind tunnel test technical field.This method includes: using tail support rod and balance to support launch weapon in six-degree-of-freedom mechanism, using double balance and double tail support to support double-body aircraft in half-arm angle of attack mechanism.According to the mass ratio of double-body aircraft and launch weapon, determine to solve six-degree-of-freedom equation for single body (launch weapon) or two bodies (launch weapon and double-body aircraft).Through the motion of six-degree-of-freedom mechanism, realize the displacement and attitude angle of launch weapon, and carry out motion compensation to the displacement of double-body aircraft, realize the pitching motion of double-body aircraft by moving half-arm angle of attack mechanism.This method has the advantages of wide simulation range, high simulation data accuracy and reliable data.

Description

Technical Field

[0001] This invention belongs to the field of experimental aerodynamics technology, and in particular relates to a method for testing the capture trajectory of a twin-fuselage aircraft. Background Technology

[0002] The uniqueness of air-launched ballistic missiles compared to conventional air-launched missiles and air-dropped weapons lies in the need to address the mechanical challenges arising from their large size and mass during separation. Air-launching is characterized by complex flow fields, intricate motion processes, and intense mutual interference. The most significant difference from traditional separation methods is that after the release of a high-mass ballistic missile, both the aircraft and the missile undergo significant linear displacement. Furthermore, the aerodynamic performance (especially stability and control effectiveness) of the aircraft and missile changes significantly due to their relative positions within the interfering flow field. Therefore, a comprehensive assessment of the subtle aerodynamic changes of both components is necessary during separation.

[0003] The capture trajectory test is a commonly used wind tunnel testing method for aircraft-missile separation. Its advantages include high predictive accuracy, obtaining test results that are essentially consistent with full-scale flight test data, and the ability to simulate complex separation conditions and special flight states of external stores using computer software. This testing technique originated in the 1960s, initially used to study the separation of external stores suspended on the wings or belly of aircraft, such as the capture trajectory test of JDAM missiles launched from an F-18C aircraft. Subsequently, it was gradually used to study the separation of internally embedded weapons, such as those in the F-35 fighter jet. In existing capture trajectory tests, the mass and volume of the parent and separated objects generally differ significantly, and the influence of the separated object on the parent is usually ignored. This type of testing method is not suitable for studying parent and separated objects with similar masses. It is necessary to develop testing techniques that simultaneously consider the mutual interference of multiple bodies. Summary of the Invention

[0004] The technical problem solved by this invention is to overcome the shortcomings of the prior art and provide a method for testing the acquisition trajectory of a twin-fuselage aircraft. This method meets the wind tunnel test requirements for the acquisition trajectory of air-launched weapons dropped from a twin-fuselage aircraft flight test platform and has the advantages of high accuracy and reliability of simulation data.

[0005] The objective of this invention is achieved through the following technical solution: a method for testing the capture trajectory of a twin-fuselage aircraft, comprising: before wind tunnel operation, using a six-degree-of-freedom motion mechanism to move an air-launched weapon model to a preset safe position, and starting wind tunnel operation; after the flow field stabilizes, using the six-degree-of-freedom motion mechanism to move the air-launched weapon model to the initial position of separation and deployment and adjust it to the initial separation attitude, obtaining the aerodynamic force and aerodynamic torque of the center of mass of the air-launched weapon model, and obtaining the aerodynamic force and aerodynamic torque of the center of mass of the twin-fuselage aircraft model; based on the aerodynamic force and aerodynamic torque of the center of mass of the air-launched weapon model and preset parameters of the air-launched weapon model, obtaining the next moment position of the air-launched weapon model; the six-degree-of-freedom motion mechanism moves the air-launched weapon model to the next moment position of the air-launched weapon model; determining whether the mass ratio of the twin-fuselage aircraft model to the air-launched weapon model is greater than a preset value; if it is greater than the preset value, outputting the capture trajectory graphic of the air-launched weapon model; if it is not greater than the preset value, outputting the capture trajectory graphic of the air-launched weapon model and the capture trajectory graphic of the twin-fuselage aircraft model.

[0006] In the above-mentioned test method for the capture trajectory of a twin-fuselage aircraft, obtaining the aerodynamic forces and aerodynamic moments of the center of mass of the air-launched weapon model includes: collecting data from the first horizon and obtaining the aerodynamic forces and aerodynamic moments of the center of mass of the air-launched weapon model based on the data from the first horizon.

[0007] In the above-mentioned method for testing the capture trajectory of a twin-fuselage aircraft, obtaining the aerodynamic forces and moments of the center of mass of the twin-fuselage aircraft model includes: collecting data from the second and third balances; obtaining the aerodynamic forces and moments of the first center of mass of the twin-fuselage aircraft model based on the data from the second balance; obtaining the aerodynamic forces and moments of the second center of mass of the twin-fuselage aircraft model based on the data from the third balance; and obtaining the aerodynamic forces and moments of the center of mass of the twin-fuselage aircraft model based on the aerodynamic forces and moments of the first and second center of mass of the twin-fuselage aircraft model.

[0008] In the above-mentioned test method for the capture trajectory of a twin-fuselage aircraft, the parameters of the preset air-launched weapon model include the initial displacement, attitude angle, velocity, angular velocity, moment of inertia, and mass of the preset air-launched weapon model.

[0009] In the above-mentioned test method for the capture trajectory of a twin-fuselage aircraft, if the mass ratio of the twin-fuselage aircraft model to the air-launched weapon model is greater than a preset value, the twin-fuselage aircraft model remains stationary, and the capture trajectory graphic of the air-launched weapon model is output.

[0010] In the above-mentioned test method for the capture trajectory of a twin-fuselage aircraft, if the mass ratio of the twin-fuselage aircraft model to the air-launched weapon model is not greater than a preset value, the six-degree-of-freedom motion equations are solved based on the aerodynamic force and aerodynamic torque of the center of mass of the twin-fuselage aircraft model and the preset parameters of the twin-fuselage aircraft model to obtain the next position of the twin-fuselage aircraft model; the relative distance between the air-launched weapon model and the twin-fuselage aircraft model is obtained based on the next position of the air-launched weapon model and the next position of the twin-fuselage aircraft model; the six-degree-of-freedom motion mechanism moves the air-launched weapon model according to the relative distance between the air-launched weapon model and the twin-fuselage aircraft model; and the capture trajectory graphics of the air-launched weapon model and the twin-fuselage aircraft model are output.

[0011] In the above-mentioned method for testing the capture trajectory of a twin-fuselage aircraft, the parameters of the preset twin-fuselage aircraft model include the initial displacement, attitude angle, velocity, angular velocity, moment of inertia, and mass of the preset twin-fuselage aircraft model.

[0012] In the above-mentioned test method for the capture trajectory of a twin-fuselage aircraft, the preset value is...

[0013] In the above-mentioned test method for the capture trajectory of a twin-fuselage aircraft, the air-launched weapon model is connected to the six-degree-of-freedom motion mechanism via the tail strut and the first horizontal plane. The twin-fuselage aircraft model is connected to the second and third horizontal planes respectively. The second and third horizontal planes are connected to the twin tail supports, and the twin tail supports are connected to the half-arm angle of attack mechanism.

[0014] In the above-mentioned test method for capturing the trajectory of a twin-fuselage aircraft, the aerodynamic forces and aerodynamic moments of the center of mass of the twin-fuselage aircraft model are obtained by the following formulas:

[0015]

[0016] Where X represents the aerodynamic force in the x-direction of the center of mass of the twin-fuselage aircraft model, Y represents the aerodynamic force in the y-direction of the center of mass of the twin-fuselage aircraft model, Z represents the aerodynamic force in the z-direction of the center of mass of the twin-fuselage aircraft model, MX represents the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model, MY represents the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model, MZ represents the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model, X1 represents the aerodynamic force in the x-direction of the first center of mass of the twin-fuselage aircraft model, Y1 represents the aerodynamic force in the y-direction of the first center of mass of the twin-fuselage aircraft model, Z1 represents the aerodynamic force in the z-direction of the first center of mass of the twin-fuselage aircraft model, X2 represents the aerodynamic force in the x-direction of the second center of mass of the twin-fuselage aircraft model, Y2 represents the aerodynamic force in the y-direction of the second center of mass of the twin-fuselage aircraft model, Z2 represents the aerodynamic force in the z-direction of the second center of mass of the twin-fuselage aircraft model, and MX1 represents the aerodynamic moment in the x-direction of the first center of mass of the twin-fuselage aircraft model. MY1 is the aerodynamic moment in the y-direction of the first center of gravity of the twin-fuselage aircraft model; MZ1 is the aerodynamic moment in the z-direction of the first center of gravity of the twin-fuselage aircraft model; MX2 is the aerodynamic moment in the x-direction of the second center of gravity of the twin-fuselage aircraft model; MY2 is the aerodynamic moment in the y-direction of the second center of gravity of the twin-fuselage aircraft model; MZ2 is the aerodynamic moment in the z-direction of the second center of gravity of the twin-fuselage aircraft model; l1 is the distance between the horizontal line containing the first center of gravity of the twin-fuselage aircraft model and the horizontal line containing the center of mass of the twin-fuselage aircraft model; l2 is the distance between the horizontal line containing the second center of gravity of the twin-fuselage aircraft model and the horizontal line containing the center of mass of the twin-fuselage aircraft model; d1 is the distance between the vertical line containing the first center of gravity of the twin-fuselage aircraft model and the vertical line containing the center of mass of the twin-fuselage aircraft model; d2 is the distance between the vertical line containing the second center of gravity of the twin-fuselage aircraft model and the vertical line containing the center of mass of the twin-fuselage aircraft model.

[0017] Compared with the prior art, the present invention has the following advantages:

[0018] (1) Existing acquisition trajectory tests for conventional aircraft-missile separation usually only consider the interference of the carrier aircraft to the missile, ignoring the interference and motion of the carrier aircraft. Based on the aircraft-missile mass ratio, this invention proposes and develops two different acquisition trajectory test strategies: one with the aircraft stationary and the other with the aircraft in motion. This broadens the test capability and improves the simulation accuracy of aircraft-missile separation.

[0019] (2) The present invention utilizes a six-degree-of-freedom motion mechanism and a half-arm angle-of-attack mechanism in a wind tunnel to realize the relative position and attitude angle of two bodies, thereby broadening the capability and scope of the capture trajectory test.

[0020] (3) The present invention utilizes a method and implementation form for measuring the synthesis of aerodynamic forces / torques on a twin-hull aircraft using a dual balance, thereby broadening the experimental capabilities. Attached Figure Description

[0021] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0022] Figure 1 This is a schematic diagram of the wind tunnel test system for capturing trajectory of a twin-fuselage aircraft provided in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the method for synthesizing aerodynamic forces and aerodynamic moments of a twin-fuselage aircraft provided in an embodiment of the present invention;

[0024] Figure 3 This is a flowchart of a capture trajectory test method for a twin-fuselage aircraft provided in an embodiment of the present invention;

[0025] Figure 4 This is a flowchart of the two-level model six-degree-of-freedom motion implementation method provided in the embodiments of the present invention. Detailed Implementation

[0026] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] The twin-fuselage test platform, with its large payload space and strong payload capacity, is suitable for various flight tests involving both flight mounting and air-launching. It can provide a usable, low-cost carrier aircraft for flight demonstration and verification of key mechanical issues such as aerodynamic interference and multi-body separation in air-launched vehicles. Due to the small fuselage size of twin-fuselage aircraft, the traditional single-tail support method for trajectory capture testing cannot be used. Therefore, a dual-balance, dual-support test scheme is required, merging data from multiple balances to obtain the composite aerodynamic forces.

[0028] Currently, solutions for the simultaneous motion of multiple bodies interfering with each other and the synthesis of dual-balance data are not yet mature. There is an urgent need to establish a test method for the capture trajectory of twin-body aircraft and to form a ground test and verification capability for the air-launched twin-body aircraft technology. This invention is proposed in this practical context.

[0029] Figure 3 This is a flowchart of a capture trajectory testing method for a twin-fuselage aircraft provided in an embodiment of the present invention. Figure 3 As shown, the method includes the following steps:

[0030] Step S100: Connect the air-launched weapon model 4 to the six-degree-of-freedom motion mechanism 1 via the tail strut 2 and the first horizontal bar 3; connect the twin-fuselage aircraft model 8 to the second horizontal bar 71 and the third horizontal bar 72 respectively; connect both the second horizontal bar 71 and the third horizontal bar 72 to the twin tail support 6; connect the twin tail support 6 to the half-arm angle-of-attack mechanism 5, as follows. Figure 1 As shown;

[0031] Step S200: Before blowing air, the air-launched weapon model 4 is moved to a preset safe position using a six-degree-of-freedom motion mechanism 1, and the wind tunnel is started to blow air.

[0032] Step S300: After the flow field stabilizes, the air-launched weapon model 4 is moved to the initial position of separation and deployment using the six-degree-of-freedom motion mechanism 1 and adjusted to the initial separation attitude. Data from the first level 3, the second level 71, and the third level 72 are collected. Based on the data from the first level 3, the aerodynamic force and aerodynamic moment of the center of mass of the air-launched weapon model 4 are obtained. Based on the data from the second level 71, the aerodynamic force and aerodynamic moment of the first center of mass of the twin-fuselage aircraft model 8 are obtained. Based on the data from the third level 72, the aerodynamic force and aerodynamic moment of the second center of mass of the twin-fuselage aircraft model 8 are obtained. Based on the aerodynamic force and aerodynamic moment of the first center of mass and the second center of mass of the twin-fuselage aircraft model 8, the aerodynamic force and aerodynamic moment of the center of mass of the twin-fuselage aircraft model 8 are obtained.

[0033] Step S400: Based on the aerodynamic force and aerodynamic torque of the center of mass of the air-launched weapon model 4 and the preset parameters of the initial displacement, attitude angle, velocity, angular velocity, moment of inertia and mass of the air-launched weapon model 4, solve the six-degree-of-freedom motion equations to obtain the next position of the air-launched weapon model 4; the six-degree-of-freedom motion mechanism 1 moves the air-launched weapon model 4 to the next position of the air-launched weapon model 4.

[0034] Step S500: If the mass ratio of the twin-fuselage aircraft model 8 to the air-launched weapon model 4 is greater than the preset value, then the twin-fuselage aircraft model 8 remains stationary, and the capture trajectory graphic of the air-launched weapon model 4 is output.

[0035] Step S600: If the mass ratio of the twin-fuselage aircraft model 8 to the air-launched weapon model 4 is not greater than a preset value, then based on the aerodynamic force / torque acting on the twin-fuselage aircraft model 8 and the preset initial displacement, attitude angle, velocity, angular velocity, moment of inertia, and mass parameters of the twin-fuselage aircraft model 8, the six-degree-of-freedom motion equations are solved to obtain the next position of the twin-fuselage aircraft model 8; the relative distance between the air-launched weapon model 4 and the twin-fuselage aircraft model 8 is obtained based on the next position of the air-launched weapon model 3 and the next position of the twin-fuselage aircraft model 8, and the six-degree-of-freedom motion mechanism 1 moves the air-launched weapon model 4 according to the relative distance between the air-launched weapon model 4 and the twin-fuselage aircraft model 8; the capture trajectory graphics of the air-launched weapon model 3 and the twin-fuselage aircraft model 8 are output.

[0036] Depending on whether the twin-fuselage aircraft model 8 is affected by the interference of the air-launched weapon model 4, two different capture trajectory test strategies are adopted. The six-degree-of-freedom motion equations of a single body (air-launched weapon model 4, first strategy) or two bodies (air-launched weapon model 4 and twin-fuselage aircraft model 8, second strategy) are solved respectively. The relative position and attitude of the two bodies at different times in the wind tunnel are realized by actuating the six-degree-of-freedom motion mechanism 1 and the half-arm angle of attack mechanism 5, and the complete trajectory lines of the twin-fuselage aircraft 8 and the air-launched weapon 4 are obtained in the two cases of no aircraft movement and aircraft movement.

[0037] Whether the catamaran aircraft model is affected by the air-launched weapon model 4 depends on the mass ratio m between the catamaran aircraft model 8 and the air-launched weapon model 4. 双体飞机 / m 空射武器 When the mass ratio is greater than 5, it is determined that the catamaran model 8 is not affected by the air-launched weapon 4. The six-degree-of-freedom equations of motion for the air-launched weapon model 4 are solved independently, and the catamaran model 8 does not move. When the mass ratio is not greater than 5, it is determined that the catamaran model 8 is affected by the air-launched weapon model. The aerodynamic forces and torques acting on the catamaran model 8 are measured using a balance. The six-degree-of-freedom equations of motion for both the air-launched weapon model and the catamaran model are solved simultaneously. The movement of the two bodies in the wind tunnel is achieved by actuating the six-degree-of-freedom motion mechanism 1 and the half-arm angle-of-attack mechanism 5.

[0038] The six-degree-of-freedom motion mechanism 1 realizes the displacement and attitude angle of the air-launched weapon model 4 and compensates for the displacement of the twin-fuselage aircraft 8; the half-arm angle of attack mechanism 5 realizes the pitch direction movement of the twin-fuselage aircraft 8; the yaw and roll direction movements of the twin-fuselage aircraft 8 are relatively small and are not simulated in the wind tunnel.

[0039] Because of its small fuselage, the twin-fuselage aircraft 6 cannot use the traditional single-tail support. It needs to use a dual-balance system with the second balance 71 and the third balance 72 for dual-tail support. The combined aerodynamic force and aerodynamic torque and corresponding coefficients are obtained by merging the data of the two balances. Then, they are substituted into the six-degree-of-freedom motion equations of the twin-fuselage aircraft 6 for solving.

[0040] The synthesis method involves shifting the aerodynamic forces and aerodynamic moments measured on two days based on their respective center of gravity to the center of mass of aircraft 8, adding the additional torque relative to the center of mass caused by the shifted aerodynamic forces, and combining them to obtain the aerodynamic forces / moment based on the center of mass of aircraft 8. After normalization, the aerodynamic force / moment coefficients are obtained.

[0041] As attached Figure 2 As shown in the figure, the center of gravity positions of the second and third balances 71 and 72, the center of mass position of the twin-fuselage aircraft model 8, and the defined coordinate system are given. The aerodynamic forces and moments measured in the three directions by the second balance 71 are X1, Y1, Z1 and MX1, MY1, MZ1, respectively. The aerodynamic forces and moments measured in the three directions by the third balance 72 are X2, Y2, Z2 and MX2, MY2, MZ2, respectively. Therefore, the aerodynamic forces and moments acting on the center of mass in the X, Y, and Z directions are as follows:

[0042]

[0043] Where X represents the aerodynamic force in the x-direction of the center of mass of the twin-fuselage aircraft model 8, Y represents the aerodynamic force in the y-direction of the center of mass of the twin-fuselage aircraft model 8, Z represents the aerodynamic force in the z-direction of the center of mass of the twin-fuselage aircraft model 8, MX represents the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model 8, MY represents the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model 8, MZ represents the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model 8, X1 represents the aerodynamic force in the x-direction of the first center of mass of the twin-fuselage aircraft model 8, Y1 represents the aerodynamic force in the y-direction of the first center of mass of the twin-fuselage aircraft model 8, Z1 represents the aerodynamic force in the z-direction of the first center of mass of the twin-fuselage aircraft model 8, X2 represents the aerodynamic force in the x-direction of the second center of mass of the twin-fuselage aircraft model 8, Y2 represents the aerodynamic force in the y-direction of the second center of mass of the twin-fuselage aircraft model 8, Z2 represents the aerodynamic force in the z-direction of the second center of mass of the twin-fuselage aircraft model 8, and MX1 represents the aerodynamic moment in the x-direction of the first center of mass of the twin-fuselage aircraft model 8. MY1 is the aerodynamic moment in the y-direction of the first center of gravity of the twin-fuselage aircraft model 8; MZ1 is the aerodynamic moment in the z-direction of the first center of gravity of the twin-fuselage aircraft model 8; MX2 is the aerodynamic moment in the x-direction of the second center of gravity of the twin-fuselage aircraft model 8; MY2 is the aerodynamic moment in the y-direction of the second center of gravity of the twin-fuselage aircraft model 8; MZ2 is the aerodynamic moment in the z-direction of the second center of gravity of the twin-fuselage aircraft model 8; l1 is the distance between the horizontal line containing the first center of gravity of the twin-fuselage aircraft model 8 and the horizontal line containing the center of mass of the twin-fuselage aircraft model 8; l2 is the distance between the horizontal line containing the second center of gravity of the twin-fuselage aircraft model 8 and the horizontal line containing the center of mass of the twin-fuselage aircraft model 8; d1 is the distance between the vertical line containing the first center of gravity of the twin-fuselage aircraft model 8 and the vertical line containing the center of mass of the twin-fuselage aircraft model 8; d2 is the distance between the vertical line containing the second center of gravity of the twin-fuselage aircraft model 8 and the vertical line containing the center of mass of the twin-fuselage aircraft model 8.

[0044] Wind tunnel tests were conducted on the capture trajectory of a twin-fuselage aircraft to obtain aerodynamic data and separation trajectory during the separation process under typical operating conditions. The specific process is shown in the attached figure. Figure 3 As shown.

[0045] Before the wind tunnel operation, the air-launched weapon model 4 was moved to a safe position away from the aircraft model 8 using a six-degree-of-freedom motion mechanism 1, according to the test conditions. Zero points were collected from three force balances, and the wind tunnel was started. After the flow field stabilized, the air-launched weapon 4 was moved to its initial separation and release position using the six-degree-of-freedom motion mechanism 1 and adjusted to its initial separation attitude. Balance data was collected, and aerodynamic coefficients were calculated. The aerodynamic forces / torques acting on the twin-fuselage aircraft were calculated by transferring the data measured by the two balances relative to their respective center of gravity to the aircraft's center of mass and then combining them.

[0046] Based on the aerodynamic forces / torques acting on the air-launched weapon model 4, as well as its initial displacement, attitude angle, velocity, angular velocity, moment of inertia, and mass, the six-degree-of-freedom motion equations are solved to obtain its position at the next moment. The motion mechanism control system drives the six-degree-of-freedom motion mechanism 1 according to the position command to move the air-launched weapon model 4 to the position at the next moment and adjust it to the corresponding attitude angle.

[0047] Based on the mass ratio of the twin-fuselage aircraft to the air-launched weapon, it is determined whether the twin-fuselage aircraft is moving. If the mass ratio is greater than 5, the twin-fuselage aircraft remains stationary, and the acquisition trajectory of the air-launched weapon is output. If the mass ratio is less than or equal to 5, based on the aerodynamic forces / torques acting on the aircraft and its initial displacement, attitude angle, velocity, angular velocity, moment of inertia, mass, and other parameters, a six-degree-of-freedom motion equation is solved to obtain its position at the next moment. Its displacement is compensated for by the relative motion of the two bodies through a six-degree-of-freedom motion mechanism. The angle of attack motion is achieved through a half-arm angle of attack mechanism 5. The attitude angle changes in the pitch and yaw directions are small and can be ignored (e.g., ...). Figure 4 As shown), the output includes the capture trajectory graphs of the two bodies and the intermediate values ​​of the test records.

[0048] Repeat the above process of capturing the two-body trajectory and actuating the mechanism until the simulated time or simulated distance limit is reached, thus completing the entire capture trajectory test. Finally, use a six-degree-of-freedom motion mechanism to move the air-launched weapon to a safe position and zero attitude angle, and use a half-arm angle-of-attack mechanism to adjust the angle of attack of the twin-fuselage aircraft model to zero before shutting down the engine.

[0049] Existing acquisition trajectory tests for conventional aircraft-missile separation typically only consider the interference of the carrier aircraft on the missile, neglecting the interference and motion of the carrier aircraft. This invention, based on the aircraft-missile mass ratio, proposes and develops two different acquisition trajectory test strategies: one with the aircraft stationary and the other with the aircraft in motion, thus broadening the test capabilities and improving the simulation accuracy of aircraft-missile separation. This invention also expands the capabilities and scope of acquisition trajectory tests by using a six-degree-of-freedom motion mechanism and a half-arm angle-of-attack mechanism in a wind tunnel to realize the relative position and attitude angle of the two aircraft. Furthermore, this invention expands the test capabilities by using a dual-balance method and implementation form to measure the synthesis of aerodynamic forces / torques acting on a twin-fuselage aircraft.

[0050] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A method for testing the capture trajectory of a twin-fuselage aircraft, characterized in that... include: Before the wind tunnel is blown, the air-launched weapon model (4) is moved to a preset safe position using a six-degree-of-freedom motion mechanism (1), and the wind tunnel is started to blow the wind. After the flow field stabilizes, the air-launched weapon model (4) is moved to the initial position of separation and deployment using a six-degree-of-freedom motion mechanism (1) and adjusted to the initial separation attitude. The aerodynamic force and aerodynamic torque of the center of mass of the air-launched weapon model (4) are obtained, as are the aerodynamic force and aerodynamic torque of the center of mass of the twin-fuselage aircraft model (8). Based on the aerodynamic force and aerodynamic torque of the center of mass of the air-launched weapon model (4) and the preset parameters of the air-launched weapon model (4), the next moment position of the air-launched weapon model (4) is obtained; the six-degree-of-freedom motion mechanism (1) moves the air-launched weapon model (4) to the next moment position of the air-launched weapon model (4); Determine whether the mass ratio of the twin-fuselage aircraft model (8) to the air-launched weapon model (4) is greater than the preset value. If it is greater than the preset value, output the capture trajectory graphic of the air-launched weapon model (4). If it is not greater than the preset value, output the capture trajectory graphic of the air-launched weapon model (4) and the capture trajectory graphic of the twin-fuselage aircraft model (8); If the mass ratio of the twin-fuselage aircraft model (8) to the air-launched weapon model (4) is not greater than the preset value, the six-degree-of-freedom motion equations are solved based on the aerodynamic force and aerodynamic torque of the center of mass of the twin-fuselage aircraft model (8) and the preset parameters of the twin-fuselage aircraft model (8) to obtain the next position of the twin-fuselage aircraft model (8); the relative distance between the air-launched weapon model (4) and the twin-fuselage aircraft model (8) is obtained based on the next position of the air-launched weapon model (4) and the next position of the twin-fuselage aircraft model (8); the six-degree-of-freedom motion mechanism (1) moves the air-launched weapon model (4) according to the relative distance between the air-launched weapon model (4) and the twin-fuselage aircraft model (8); the capture trajectory graph of the air-launched weapon model (4) and the capture trajectory graph of the twin-fuselage aircraft model (8) are output. The aerodynamic forces and aerodynamic moments of the center of mass of the air-launched weapon model (4) include: Data from the first day's balance (3) was collected, and the aerodynamic force and aerodynamic torque of the center of mass of the air-launched weapon model (4) were obtained based on the data from the first day's balance (3). The aerodynamic forces and aerodynamic moments of the center of mass of the twin-fuselage aircraft model (8) include: Data from the second day's balance (71) and the third day's balance (72) are collected. Based on the data from the second day's balance (71), the aerodynamic forces and aerodynamic torques of the first center of gravity of the twin-fuselage aircraft model (8) are obtained. Based on the data from the third day's balance (72), the aerodynamic forces and aerodynamic torques of the second center of gravity of the twin-fuselage aircraft model (8) are obtained. Based on the aerodynamic forces and aerodynamic torques of the first center of gravity and the second center of gravity of the twin-fuselage aircraft model (8), the aerodynamic forces and aerodynamic torques of the center of mass of the twin-fuselage aircraft model (8) are obtained. The aerodynamic forces and aerodynamic moments of the center of mass of the twin-fuselage aircraft model (8) are obtained by the following formulas: Where X is the aerodynamic force in the x-direction of the center of mass of the twin-fuselage aircraft model (8), Y is the aerodynamic force in the y-direction of the center of mass of the twin-fuselage aircraft model (8), Z is the aerodynamic force in the z-direction of the center of mass of the twin-fuselage aircraft model (8), MX is the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model (8), MY is the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model (8), MZ is the aerodynamic moment in the x-direction of the center of mass of the twin-fuselage aircraft model (8), and X1 is the first center of mass of the twin-fuselage aircraft model (8). The aerodynamic force in the x-direction, Y1 is the aerodynamic force in the y-direction of the first center of gravity of the twin-fuselage aircraft model (8), Z1 is the aerodynamic force in the z-direction of the first center of gravity of the twin-fuselage aircraft model (8), X2 is the aerodynamic force in the x-direction of the second center of gravity of the twin-fuselage aircraft model (8), Y2 is the aerodynamic force in the y-direction of the second center of gravity of the twin-fuselage aircraft model (8), Z2 is the aerodynamic force in the z-direction of the second center of gravity of the twin-fuselage aircraft model (8), and MX1 is the aerodynamic moment in the x-direction of the first center of gravity of the twin-fuselage aircraft model (8). MY1 is the aerodynamic moment in the y-direction of the first center of gravity of the twin-fuselage aircraft model (8), MZ1 is the aerodynamic moment in the z-direction of the first center of gravity of the twin-fuselage aircraft model (8), MX2 is the aerodynamic moment in the x-direction of the second center of gravity of the twin-fuselage aircraft model (8), MY2 is the aerodynamic moment in the y-direction of the second center of gravity of the twin-fuselage aircraft model (8), MZ2 is the aerodynamic moment in the z-direction of the second center of gravity of the twin-fuselage aircraft model (8), l1 is the distance between the horizontal line where the first center of gravity of the twin-fuselage aircraft model (8) is located and the horizontal line where the center of mass of the twin-fuselage aircraft model (8) is located, l2 is the distance between the horizontal line where the second center of gravity of the twin-fuselage aircraft model (8) is located and the horizontal line where the center of mass of the twin-fuselage aircraft model (8) is located, d1 is the distance between the vertical line where the first center of gravity of the twin-fuselage aircraft model (8) is located and the vertical line where the center of mass of the twin-fuselage aircraft model (8) is located, d2 is the distance between the vertical line where the second center of gravity of the twin-fuselage aircraft model (8) is located and the vertical line where the center of mass of the twin-fuselage aircraft model (8) is located.

2. The method for testing the acquisition trajectory of a twin-fuselage aircraft according to claim 1, characterized in that: The parameters of the preset air-launched weapon model (4) include the initial displacement, attitude angle, velocity, angular velocity, moment of inertia, and mass of the preset air-launched weapon model (4).

3. The method for testing the acquisition trajectory of a twin-fuselage aircraft according to claim 1, characterized in that: If the mass ratio of the twin-fuselage aircraft model (8) to the air-launched weapon model (4) is greater than the preset value, the twin-fuselage aircraft model (8) will remain stationary and the capture trajectory graphic of the air-launched weapon model (4) will be output.

4. The method for testing the acquisition trajectory of a twin-fuselage aircraft according to claim 1, characterized in that: The parameters of the preset twin-fuselage aircraft model (8) include the initial displacement, attitude angle, velocity, angular velocity, moment of inertia, and mass of the preset twin-fuselage aircraft model (8).

5. The method for testing the acquisition trajectory of a twin-fuselage aircraft according to claim 1, characterized in that: The preset value is 5.

6. The method for testing the acquisition trajectory of a twin-fuselage aircraft according to claim 1, characterized in that: The air-launched weapon model (4) is connected to the six-degree-of-freedom motion mechanism (1) via the tail strut (2) and the first scale (3). The twin-fuselage aircraft model (8) is connected to the second scale (71) and the third scale (72) respectively. The second scale (71) and the third scale (72) are both connected to the twin tail support (6). The twin tail support (6) is connected to the half-arm angle of attack mechanism (5).

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