Method, device and electronic equipment for longitudinal aerodynamic force rapid analysis of variable sweep wing trans-medium aircraft and water-exiting post-attitude stability control

Abstract

The application discloses a method and device for longitudinal aerodynamic force rapid analysis and water-exit attitude stability control of a variable-sweep wing trans-medium aircraft and electronic equipment, and comprises the following steps: aerodynamic analysis is carried out on the wings, fuselage and elevators of the aircraft separately; the aerodynamic force analysis of the wings is carried out by using open-source aerodynamic analysis software XFLR5 software, and the results of the aerodynamic force analysis of the wings in the multi-physical field simulation and computational fluid dynamics software STAR-CCM+ software are compared and verified; a mathematical model of the aircraft is established, and the control problem of the aircraft is mathematically abstracted; an extended state observer (ESO) is designed to observe the disturbance and the nonlinearity of the model, and a backstepping controller is designed to control the attitude of the variable-sweep wing trans-medium aircraft, so that the aircraft is rapidly stabilized. The application can significantly improve the aerodynamic parameter acquisition efficiency, accelerate the theoretical verification process, and effectively solve the stability control of the variable-sweep wing trans-medium aircraft in the water-exit stage.

Description

Technical Field

[0001] This invention belongs to the field of cross-medium aircraft modeling and control technology, and relates to a method, device and electronic equipment for rapid longitudinal aerodynamic analysis and attitude stability control after water exit of a variable-sweep wing cross-medium aircraft. In particular, it includes a method and verification method for obtaining aerodynamic parameters by combining computational fluid dynamics (CFD) and lifting surface theory, as well as a cross-medium transition control system based on an active disturbance rejection extended state observer (ESO) and backstepping method, which is used to solve the attitude stability problem of variable-sweep wing cross-medium aircraft after water exit. Background Technology

[0002] With the rapid development of modern technology, cross-medium aircraft, as an innovative type of unmanned equipment, have gradually become a research hotspot. Cross-medium aircraft possess the dual capabilities of air and underwater flight and can freely switch between the two media, achieving bidirectional crossing of water and air media.

[0003] Currently, cross-medium aircraft mainly include rotorcraft cross-medium aircraft, fixed-wing cross-medium aircraft, hybrid-wing cross-medium aircraft, and variable-sweep wing cross-medium aircraft. Among them, the special configuration of variable-sweep wing cross-medium aircraft can reduce water resistance when entering and exiting water, making water entry and exit smoother, and it also has a higher speed in the air.

[0004] However, despite the significant advantages of variable-sweep wing transmedium vehicles in the transmedium domain, they still face numerous challenges in practical applications. Because variable-sweep wing transmedium vehicles need to operate at different angles of attack and sweep angles, obtaining their aerodynamic coefficients is a labor-intensive process. Simultaneously, obtaining hydrodynamic coefficients also requires considerable experimental effort. Currently, most research on variable-sweep wing transmedium vehicles exhibits a disconnect between underwater and aerial phases, with relatively few studies comprehensively considering both. Therefore, a comprehensive consideration of the hydrodynamic and aerodynamic analyses of variable-sweep wing vehicles is particularly important.

[0005] Furthermore, variable-sweep wing cross-medium aircraft often face problems of large initial pitch angles and attitude instability after being ejected from the water, which seriously affects their mission performance. Therefore, in-depth research on the attitude stability control of variable-sweep wing aircraft after exiting the water has become a critical issue that urgently needs to be addressed. Summary of the Invention

[0006] The purpose of this invention is to propose a method, device, and electronic equipment for rapid longitudinal aerodynamic analysis and post-launch attitude stabilization control of a variable-sweep wing cross-medium aircraft. This addresses two major technical challenges in the research of variable-sweep wing cross-medium aircraft: First, the efficiency of aerodynamic analysis. Based on a rapid analysis method combining computational fluid dynamics (CFD) and lifting surface theory, and through multiphysics simulation, detailed flow field simulation using the CFD software STAR-CCM+, and rapid aerodynamic calculations using the open-source aerodynamic analysis software XFLR5, the longitudinal aerodynamic coefficients (including lift coefficient CL, drag coefficient CD, etc.) of the variable-sweep wing aircraft are efficiently obtained, making it suitable for the rapid design and control verification of small variable-sweep wing aircraft. Second, the stability problem after launch. Addressing the phenomenon of large pitch angles and unstable attitude after launch, an innovative backstepping controller based on an extended state observer (ESO) is designed. By estimating external disturbances and model uncertainties in real time, the variable-sweep wing cross-medium aircraft adjusts its attitude promptly under the controller's control after launch, enabling the aircraft to enter a stable state.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0008] The present invention provides a method for rapid analysis of longitudinal aerodynamic forces and attitude stabilization control after water exit for a variable-sweep wing transmedium aircraft, comprising the following steps:

[0009] S1. Modeling and Aerodynamic Analysis of the Variable-Sweep Wing Transmedium Aircraft: The wing of the variable-sweep wing transmedium aircraft is modeled in the 3D modeling software SOLIDWORKS, and the aerodynamic analysis of the wing of the variable-sweep wing transmedium aircraft is performed using the multiphysics simulation and computational fluid dynamics software STAR-CCM+.

[0010] S2. Variable-sweep wing cross-medium aircraft fuselage modeling and aerodynamic analysis stage: The fuselage of the variable-sweep wing cross-medium aircraft is modeled in the open-source aerodynamic analysis software XFLR5, and a rapid aerodynamic analysis of the fuselage of the variable-sweep wing cross-medium aircraft is performed.

[0011] S3. Aerodynamic analysis of elevator of variable-sweep wing cross-medium aircraft: Select the corresponding elevator airfoil in the open-source aerodynamic analysis software XFLR5 and perform rapid aerodynamic analysis of the elevator of variable-sweep wing cross-medium aircraft.

[0012] S4. Aerodynamic Analysis and Verification Phase: The aerodynamic analysis of the wing was performed using the open-source aerodynamic analysis software XFLR5, and the results were compared and verified with the aerodynamic analysis of the wing in the multiphysics simulation and computational fluid dynamics software STAR-CCM+.

[0013] S5. Mathematical Model Establishment and Control Problem Abstraction Stage of Variable-Sweep Wing Trans-medium Aircraft: Establish the mathematical model of the variable-sweep wing trans-medium aircraft and perform mathematical abstraction on the control problem of the variable-sweep wing trans-medium aircraft.

[0014] S6. Controller Design Stage: To address the issues of large pitch angle, poor attitude, and instability of the variable-sweep wing transmedium aircraft after it emerges from the water, an extended state observer (ESO) is designed to observe disturbances and the nonlinearity of the model. Based on this, an inverse stepping controller is designed to control the attitude of the variable-sweep wing transmedium aircraft, enabling the aircraft to stabilize quickly.

[0015] Specifically, in step S1, the wing of the variable-sweep wing transmedium aircraft is modeled in three dimensions and subjected to aerodynamic analysis. The specific process includes:

[0016] S1.1. Perform 3D modeling of the AG08 airfoil using the 3D modeling software SOLIDWORKS;

[0017] S1.2. Import the established AG08 airfoil into the multiphysics simulation and computational fluid dynamics software STAR-CCM+, and divide the computational domain of the fluid into the flow field region for simulating airflow, the encrypted region for intensive analysis of the airfoil, and the transition region for intermediate transition processes.

[0018] S1.3. Perform relatively coarse meshing on the flow field region and transition region, fine meshing on the wing, and perform surface control on the wing to refine the mesh on the wing surface and set the wing mesh to an overlapping mesh.

[0019] S1.4 Select the physical model and set the material properties. Use the Spalart-Allmaras turbulence model and the ideal gas model. Select three-dimensional space mode for simulation, set the time to be constant, and set the dynamic viscosity and thermal conductivity of the gas.

[0020] S1.5 Set the simulation conditions for aerodynamics, including initial conditions such as velocity, static temperature, turbulence specification, and pressure. Set the flow field inlet as a velocity inlet, the other surfaces as symmetry surfaces, the six outer surfaces of the overlapping mesh as overlapping meshes, and the inner surface, which is the wing surface, as a wall surface.

[0021] S1.6. By changing the sweep angle and angle of attack of the wing, conduct experimental simulations of the variable sweep wing transmedium aircraft wing and record the aerodynamic parameter data.

[0022] Specifically, in step S2, the fuselage of the variable-sweep wing transmedium aircraft is modeled and its aerodynamics analyzed. The specific process includes:

[0023] S2.1 Since the fuselage of the variable-sweep wing transmedia aircraft is a rotating body, it can be regarded as a combination of a cylinder and a hemisphere, which is a relatively simple model. Therefore, the fuselage is simply modeled in the open-source aerodynamic analysis software XFLR5. First, 7 points are determined in the x-direction to determine the key points of the length and cross-section of the variable-sweep wing transmedia aircraft fuselage. At each cross-section, the coordinates of 5 points are selected to determine the cross-sectional shape.

[0024] S2.2 Since the open-source aerodynamics analysis software XFLR5 requires drawing the wings when performing 3D modeling, the wingspan of the wings is reduced to the fuselage surface, thereby indirectly establishing the fuselage model.

[0025] S2.3. Set simulation conditions, set the airflow velocity to 25m / s, set the analysis range of the angle of attack to -18° to 18°, and perform batch aerodynamic analysis on the selected angle of attack;

[0026] S2.4 Conduct experimental simulations of the fuselage of the variable-sweep wing transmedium aircraft and record the aerodynamic parameter data.

[0027] Specifically, in step S3, the elevator of the variable-sweep wing trans-medium aircraft is selected and aerodynamically analyzed using the open-source aerodynamic analysis software XFLR5. The specific process includes:

[0028] S3.1 In the open-source aerodynamic analysis software XFLR5, select the NACA0012 airfoil and first perform a two-dimensional aerodynamic analysis of the NACA0012 airfoil over a wide range of Reynolds numbers.

[0029] S3.2 Set the elevator span, set the elevator simulation conditions, and set the simulation range of its Reynolds number and angle of attack;

[0030] S3.3 Perform aerodynamic analysis on the elevator and record the aerodynamic parameter data;

[0031] Specifically, in step S4, the open-source aerodynamic analysis software XFLR5 is used to perform aerodynamic analysis of the AG08 airfoil under specific operating conditions, and the aerodynamic analysis of the airfoil is compared and verified with that of the multiphysics simulation and computational fluid dynamics software STAR-CCM+.

[0032] Specifically, in step S4, the open-source aerodynamic analysis software XFLR5 is used to perform aerodynamic analysis of the AG08 airfoil under specific operating conditions, and the results are compared and verified with the aerodynamic analysis of the airfoil performed by the multiphysics simulation and computational fluid dynamics software STAR-CCM+. This includes:

[0033] S4.1 Export the AG08 airfoil coordinate data in Profili2 software;

[0034] S4.2 Open the open-source aerodynamic analysis software XFLR5, load the coordinate data file of AG08, set the corresponding Reynolds number and Mach number, set a series of Reynolds numbers, perform two-dimensional aerodynamic analysis on the AG08 airfoil with an angle of attack range of -15° to 15°, and record the aerodynamic data corresponding to the Reynolds number.

[0035] S4.3 Perform aerodynamic simulations at corresponding Reynolds numbers for wings with different aspect ratios, record the data, and compare the results of the two-dimensional airfoil analysis with the three-dimensional wing analysis results at different aspect ratios with the aerodynamic coefficients in the multiphysics simulation and computational fluid dynamics software STAR-CCM+ with a sweep angle of 0 to verify the reliability of the aerodynamic analysis data in the multiphysics simulation and computational fluid dynamics software STAR-CCM+.

[0036] Specifically, in step S5, a mathematical model is performed on the variable-sweep wing transmedium aircraft, and mathematical abstraction is carried out for the corresponding control problem, including:

[0037] S5.1, based on the velocity V of the variable-sweep wing transmedium aircraft b The angular velocity ω of a variable-sweep wing transmedium aircraft is given by: ω = [p, q, r] T The static moment S of the variable-sweep wing transmedium aircraft is analyzed in terms of its forces and angular momentum. Perform analysis;

[0038] S5.2. Calculate the forces and moments of the variable-sweep wing transmedium aircraft based on the forces and moments of momentum.

[0039] S5.3. Based on the forces and moments acting on the variable-sweep wing transmedium aircraft, the longitudinal dynamic equations of the variable-sweep wing transmedium aircraft are obtained:

[0040]

[0041] S5.4 The research problem is mathematically abstracted. The variable-sweep wing cross-medium aircraft has a large pitch angle after emerging from the water, resulting in poor attitude and instability. Therefore, attitude control of the variable-sweep wing cross-medium aircraft is necessary. The problem can be simplified to controlling the speed of the variable-sweep wing cross-medium aircraft through thrust control and controlling the pitch angle through the elevator to maintain attitude stability. The variable-sweep wing cross-medium aircraft system is divided into an inner loop and an outer loop. The inner loop uses the pitch angle as the feedback variable, and the outer loop uses the speed as the feedback variable. The target pitch angle θ is designed. d The inner loop controller enables the pitch angle to track the target pitch angle θ. d Design target angle of attack α dThe target velocity V is obtained by balancing. d The outer loop controller enables the variable-sweep wing transmedium aircraft to track the target velocity V. d The problem can be abstracted into the following mathematical form:

[0042] For the outer loop velocity loop, the control equation is in the form of: in d1 represents the external disturbance; the outer loop control problem is to design a thrust controller to make the velocity V of the variable-sweep wing transmedium aircraft track the target velocity V. d ,

[0043] For the inner pitch loop, the control equations are as follows:

[0044]

[0045] The definitions of each coefficient are as follows:

[0046]

[0047] The inner loop control problem involves designing an elevator controller to enable the pitch angle θ of a variable-sweep wing transmedium aircraft to track the target pitch angle θ. d .

[0048] Specifically, in step S6, an extended state observer (ESO) is designed to observe the disturbances and nonlinearities in the model, and a controller is designed using the backstepping method to make the velocity V of the variable-sweep wing transmedium aircraft track the target velocity V. d This enables the pitch angle θ of the variable-sweep wing transmedium aircraft to track the target pitch angle θ. d The specific steps include:

[0049] S6.1, Targeting ESO1 is designed to perform real-time observation of the f1+d1 disturbance term and the nonlinear term in this equation. The design form of ESO1 is as follows:

[0050]

[0051] Where z1 is used to estimate V, and z2 is used to estimate f1+d1;

[0052] S6.2, Targeting ESO2 was designed to address the perturbation term and the nonlinear term f2+d2+bδ in the equation. e -b0δ e For real-time observation, ESO2 is designed as follows:

[0053]

[0054] Where z3 is used to estimate q, and z4 is used to estimate f2+d2+(b-b0)δ e ;

[0055] S6.3, Design a controller using the backstepping method to enable the speed V of the variable-sweep wing transmedia aircraft to track the target speed V. d : via e1=VV d Design Lyapunov functions By differentiating V1, the thrust controller T can be obtained. Differentiating V1 yields: The term f1+d1 can be given by the output z2 of the extended state observer ESO1, and the controller can be designed in the following form: Where ω1 = f1 + d1, which is given by the output z2 of the extended state observer ESO1;

[0056] S6.4, Design error e2=θ-θ d e3 = qq f,vir e4 = q f,vir -q vir Design Lyapunov functions The intermediate controller q is obtained by differentiating V2. vir And the obtained intermediate controller q vir q is obtained through a filter. f,vir Design Lyapunov functions The elevator controller δ is obtained by differentiating V3. e The specific steps are as follows:

[0057] S6.4.1 Design Lyapunov functions Differentiating V2, we get:

[0058]

[0059] Among them, the intermediate controller q vir It can be designed as At this point, the Lyapunov function is

[0060] S6.4.2 Design Lyapunov functions Differentiating V3, we get:

[0061]

[0062] To simplify the expression, ω is used. d Replace f2+d2+bδ e -b0δ e ω dThe controller can be designed as follows, given by the output z4 of the extended state observer ESO2:

[0063] Therefore, the controller design for the intermediate controller and the elevator is as follows:

[0064]

[0065] The present invention provides a device for rapid longitudinal aerodynamic analysis and post-emergence attitude stabilization control of a variable-sweep wing transmedium aircraft, comprising:

[0066] The aerodynamic analysis module is used to perform aerodynamic analyses on the wings, fuselage, and elevators of a variable-sweep wing cross-medium aircraft. Specifically, the wing modeling and aerodynamic analysis includes modeling the aircraft's wings in the 3D modeling software SOLIDWORKS and performing aerodynamic analysis on the wings using the multiphysics simulation and computational fluid dynamics software STAR-CCM+. The fuselage modeling and aerodynamic analysis involves modeling the fuselage of the variable-sweep wing cross-medium aircraft in the open-source aerodynamic analysis software XFLR5 and performing rapid aerodynamic analysis on the fuselage. The elevator aerodynamic analysis involves selecting the appropriate elevator airfoil in the open-source aerodynamic analysis software XFLR5 and performing rapid aerodynamic analysis on the elevator.

[0067] The verification module is used to compare and verify the results of aerodynamic analysis of the wing using the open-source aerodynamic analysis software XFLR5 and the results of multiphysics simulation and aerodynamic analysis of the wing using the computational fluid dynamics software STAR-CCM+.

[0068] The Model Establishment and Control Problem Abstraction Module is used for the establishment and control of mathematical models of variable-sweep wing cross-medium aircraft, including establishing a mathematical model of the variable-sweep wing cross-medium aircraft and mathematically abstracting the control problem of the variable-sweep wing cross-medium aircraft.

[0069] The design module is used for controller design. It includes designing an extended state observer (ESO) to observe disturbances and nonlinearities of the model, addressing the problems of large pitch angles, poor attitude, and instability of the variable-sweep wing transmedium aircraft after it emerges from the water. Based on this, an inverse stepping controller is designed to control the attitude of the variable-sweep wing transmedium aircraft, enabling it to stably enter the cruise or climb phase.

[0070] An electronic device of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described method for rapid longitudinal aerodynamic analysis of a variable-sweep wing transmedium aircraft and attitude stabilization control after water exit.

[0071] The present invention provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described method for rapid longitudinal aerodynamic analysis of a variable-sweep wing transmedium aircraft and attitude stabilization control after water exit.

[0072] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0073] 1. In performing aerodynamic analysis on variable-sweep wing transmedium aircraft, this invention adopts the approach of performing aerodynamic analysis on the wing, fuselage, and elevator separately, and uses a method of collaborative analysis and verification with the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+ and the open-source aerodynamic analysis software XFLR5, thereby improving the efficiency of analyzing variable-sweep wing transmedium aircraft.

[0074] 2. In terms of control, this invention uses an extended state observer (ESO) from the active disturbance rejection control concept to dynamically observe disturbances and nonlinear terms in the model. Compared with using neural networks to observe disturbances and nonlinear terms, this saves resources and improves efficiency.

[0075] 3. This invention employs a backstepping method to design a controller for controlling the attitude of a variable-sweep wing transmedium aircraft, enabling the aircraft to quickly enter a stable state after emerging from the water. Attached Figure Description

[0076] Figure 1 This is a flowchart of an embodiment of the aerodynamic analysis and attitude stabilization control of the variable-sweep wing aircraft of the present invention.

[0077] Figure 2 This is an airflow field diagram of a variable-sweep wing transmedium aircraft drawn using the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+.

[0078] Figure 3 This is a diagram of the encrypted region of a variable-sweep wing transmedium aircraft drawn using the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+.

[0079] Figure 4 This is a diagram of the transition region between the airflow field region and the wing region, drawn using the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+.

[0080] Figure 5 This is a rendering of the wing mesh created using the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+.

[0081] Figure 6 This is a structural diagram of the present invention when modeling the fuselage of a variable-sweep wing transmedium aircraft using the open-source aerodynamic analysis software XFLR5.

[0082] Figure 7 This is a summary chart of the lift coefficients of the AG08 airfoil with a sweep angle of 0 when the aerodynamic coefficients of the variable-sweep wing transmedium aircraft were calculated using the open-source aerodynamic analysis software XFLR5.

[0083] Figure 8 This is a rendering of the effect of the invention on the pitch angle of the controller for a variable-sweep wing transmedium aircraft.

[0084] Figure 9 This is a diagram illustrating the effect of the invention on the pitch rate of the controller for a variable-sweep wing transmedium aircraft.

[0085] Figure 10 This is a diagram illustrating the effect of the invention on the altitude of a variable-sweep wing transmedium aircraft after designing a controller.

[0086] Figure 11 This is a diagram illustrating the effect of the invention on the design of the controller for the angle of attack of a variable-sweep wing transmedium aircraft.

[0087] Figure 12 This is a diagram illustrating the effect of the design controller for the flight path angle of the variable-sweep wing transmedium aircraft based on the present invention.

[0088] Figure 13 This is a diagram illustrating the effect of the invention on the speed of a variable-sweep wing transmedium aircraft after designing a controller. Detailed Implementation

[0089] This invention provides a method, device, and electronic equipment for rapid longitudinal aerodynamic analysis and attitude stabilization control of a variable-sweep wing cross-medium aircraft after it emerges from water. The method includes: conducting separate aerodynamic analyses of the wing, fuselage, and elevator of the variable-sweep wing cross-medium aircraft; comparing and verifying the reliability of the AG08 wing data analyzed by the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+ using the relatively mature open-source aerodynamic analysis software XFLR5; after obtaining the aerodynamic coefficients of the variable-sweep wing cross-medium aircraft, establishing a longitudinal nonlinear mathematical model of the aircraft; abstracting the longitudinal mathematical model of the variable-sweep wing aircraft for the control problem; designing an extended state observer (ESO) based on the abstracted mathematical model to dynamically observe the system's disturbance and nonlinear terms; and designing a controller using the backstepping method to ensure the system meets the tracking conditions.

[0090] The present invention will now be described in further detail with reference to the accompanying drawings.

[0091] Figure 1 This is a flowchart illustrating the aerodynamic analysis and controller design of a variable-sweep wing transmedium aircraft based on the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+ and the open-source aerodynamic analysis software XFLR5, as described in this invention. Figure 1 As shown, the method in this embodiment includes the following steps:

[0092] S1. Modeling and Aerodynamic Analysis of the Variable-Sweep Wing Transmedium Aircraft: The wing of the variable-sweep wing transmedium aircraft is modeled in the 3D modeling software SOLIDWORKS, and the aerodynamic analysis of the aircraft's wing is performed using the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+.

[0093] S2. Variable-sweep wing cross-medium aircraft fuselage modeling and aerodynamic analysis stage: The fuselage of the variable-sweep wing cross-medium aircraft is modeled in the open-source aerodynamic analysis software XFLR5, and a rapid aerodynamic analysis of the fuselage of the variable-sweep wing cross-medium aircraft is performed.

[0094] S3. Aerodynamic analysis of elevator of variable-sweep wing transmedium aircraft: Select the corresponding elevator airfoil in the open-source aerodynamic analysis software XFLR5 and perform rapid aerodynamic analysis of the elevator of the aircraft.

[0095] S4. Aerodynamic Analysis and Verification Phase: The aerodynamic analysis of the variable-sweep wing transmedium aircraft was performed using the open-source aerodynamic analysis software XFLR5, and the results were compared and verified with the wing aerodynamic analysis results in the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+.

[0096] S5. Mathematical Model Establishment and Control Problem Abstraction Stage of Variable-Sweep Wing Trans-medium Aircraft: Establish the mathematical model of the variable-sweep wing trans-medium aircraft and describe the control problem of the variable-sweep wing trans-medium aircraft.

[0097] S6. Controller Design Stage: To address the issue of poor and unstable attitude of the variable-sweep wing transmedium aircraft after it emerges from the water, an extended state observer (ESO) is designed to observe disturbances and the nonlinearity of the model. Based on this, an inverse stepping controller is designed to adjust the attitude of the variable-sweep wing transmedium aircraft.

[0098] According to step S1, the specific steps for modeling the variable-sweep wing of the trans-medium aircraft in the 3D modeling software SOLIDWORKS and performing aerodynamic simulation in the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+ include:

[0099] S1.1 The AG08 airfoil was modeled in 3D using the 3D modeling software SOLIDWORKS. To improve the computational efficiency of the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+, the modeling size of the airfoil was scaled. After obtaining the data, the aerodynamic coefficient of the aircraft was obtained by unitizing the size. When modeling, the airfoil span was 0.63404m and the airfoil chord length was 0.10619m.

[0100] S1.2. Import the created AG08 airfoil into the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+. In the component options, select "Create New Body Component" to divide the computational domain of the fluid into three regions: the flow field region simulating airflow, the encrypted region for finer analysis of the airfoil, and the transition region for intermediate transition processes. The flow field region is as follows: Figure 2 As shown, the encrypted area of ​​the wing is as follows Figure 3 As shown, the intermediate transition area is as follows Figure 4 As shown;

[0101] S1.3. Perform relatively coarse meshing on the flow field region and transition region, fine meshing on the wing, and control the wing introduction surface to refine the mesh on the wing surface, and set the wing mesh to an overlapping mesh.

[0102] S1.3.1 Regarding the background mesh, select the surface reconstruction and cut volume mesh element generator. In the default control, set the base size to 0.5m, and the target surface size and minimum surface size to 100%. In the custom control, select the transition zone as the custom volume control, and set its size to 5% of the base size.

[0103] S1.3.2 Regarding the settings for wing mesh generation, the mesh generator is selected as Surface Reconstruction, Cut Volume Mesh Element Generator, and Prism Layer Mesh Generator. In the default settings, the base size is set to 0.5m, the target surface size is set to 100%, the minimum surface size is set to 25%, the number of prism layers is set to 15, the near-wall thickness of the prism layer is set to 0.0001m, and the total thickness of the prism layer is set to 1% of the base percentage. The wing mesh effect is as follows: Figure 5 As shown;

[0104] S1.4 Select the physical model and set the material properties. Use the Spalart-Allmaras turbulence model and the ideal gas model. Select three-dimensional space mode for simulation, time is constant, the dynamic viscosity of the gas is set to 4.58E-5Pa-s, and the thermal conductivity is set to 0.0638414W / mK.

[0105] S1.5 Set the simulation conditions for aerodynamics: velocity is set to 25 m / s, static temperature is set to 300 K, turbulent viscosity ratio is set to 10, the flow field inlet is set as a velocity inlet, other surfaces are set as symmetry surfaces, the six outer surfaces of the overlapping mesh are set as overlapping meshes, and the inner surface is the wing surface, set as a wall surface.

[0106] S1.6. With wing sweep angles of 0°, 10°, 30°, 45°, 60°, 75°, and 90°, and wing angle of attack varying from -22° to 22° in 2° increments, conduct experimental simulations of the aircraft wing and record the aerodynamic parameter data; partial data on lift coefficient are shown in Table 1, and partial data on drag coefficient are shown in Table 2.

[0107] Table 1. Partial data on wing lift coefficient

[0108]

[0109] Table 2 Partial Data on Wing Drag Coefficient

[0110]

[0111]

[0112] According to step S2, the specific steps for performing aerodynamic simulation of the variable-sweep wing aircraft fuselage in the open-source aerodynamic analysis software XFLR5 include:

[0113] S2.1 The fuselage is modeled in the open-source aerodynamics analysis software XFLR5. Seven points are determined in the x-direction to define the key points for the fuselage length and cross-section. At each cross-section, the coordinates of five points are selected to determine the cross-sectional shape. The coordinates in the x-direction are shown in Table 3, and the coordinates at the cross-sections are shown in Table 4. In Table 4, the vertical columns represent the order of the points selected in the x-direction, the first horizontal row represents the y-coordinate of that point, and the second horizontal row represents the z-coordinate of that point. The final fuselage shape is as follows: Figure 6 As shown:

[0114] Table 3. X-axis coordinates of the fuselage

[0115]

[0116] Table 4 Key Point Cross-Section Coordinates

[0117]

[0118]

[0119] S2.2 Since the open-source aerodynamics analysis software XFLR5 must draw the wing when performing 3D modeling, the wingspan of the wing is reduced to the surface of the fuselage to indirectly establish the fuselage model. The NACA0012 airfoil is selected for the wing, and the wingspan is reduced to make it close to the surface of the fuselage to achieve the effect of indirectly analyzing the aerodynamic forces of the fuselage.

[0120] S2.3. Set simulation conditions, set the airflow velocity to 25m / s, set the analysis range of the angle of attack to -18° to 18°, and perform batch aerodynamic analysis on the selected angle of attack;

[0121] S2.4. Conduct experimental simulations on the aircraft fuselage and record the aerodynamic parameter data. The data recording results are shown in Table 5.

[0122] Table 5. Partial data on fuselage lift coefficient and drag coefficient.

[0123]

[0124] According to step S3, the specific steps for performing aerodynamic simulation of the elevator of a variable-sweep wing transmedium aircraft in the open-source aerodynamic analysis software XFLR5 include:

[0125] S3.1 In the open-source aerodynamics analysis software XFLR5, select direct airfoil analysis, select the NACA0012 airfoil in the NACA airfoil library, select batch analysis, and perform a series of Reynolds number analyses on the airfoil. The range of Reynolds numbers should include the Reynolds numbers for the subsequent three-dimensional analysis.

[0126] S3.2 Perform three-dimensional analysis on the NACA0012 airfoil, set the speed to 25m / s, the Reynolds number to 1700000, and begin aerodynamic analysis of the elevator;

[0127] S3.3 The elevator angle of attack was changed from -15° to 15°. An experimental simulation was performed on the aircraft elevator, and the aerodynamic parameter data were recorded. Partial data of the lift coefficient and drag coefficient are shown in Table 6.

[0128] Table 6. Partial Data on Elevator Lift and Drag Coefficients

[0129]

[0130] According to step S4, the open-source aerodynamic analysis software XFLR5 is used to perform aerodynamic analysis of the AG08 airfoil under specific operating conditions, and the results are compared and verified with the aerodynamic analysis of the airfoil performed by the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+. The process specifically includes:

[0131] S4.1. Export the AG08 airfoil as a .dat file in the airfoil design software Profili2. First, perform a two-dimensional aerodynamic analysis on the AG08 airfoil in the open-source aerodynamic analysis software XFLR5 and record the analysis data.

[0132] S4.2. Since the two-dimensional aerodynamic analysis of the open-source aerodynamic analysis software XFLR5 is based on the theory of infinite wings, its aerodynamic coefficients will theoretically be larger than those of three-dimensional wings. Therefore, it is necessary to perform aerodynamic analysis on three-dimensional wings with different aspect ratios. The specific steps are as follows:

[0133] S4.2.1 In the open-source aerodynamic analysis software XFLR5, change the wing aspect ratio, set the wing aspect ratio to 20, and set the operating conditions as follows: sweep angle is 0, air speed is 25m / s, air density is 1.225kg / m3, perform aerodynamic analysis on the wing and record its lift coefficient;

[0134] S4.2.2 In the open-source aerodynamic analysis software XFLR5, change the wing aspect ratio, set the wing aspect ratio to 10, and set the operating conditions as follows: sweep angle is 0, air speed is 25m / s, air density is 1.225kg / m3, perform aerodynamic analysis on the wing and record its lift coefficient;

[0135] S4.2.3 In the open-source aerodynamic analysis software XFLR5, change the wing aspect ratio, set the wing aspect ratio to 6, and set the operating conditions as follows: sweep angle of 0, air speed of 25 m / s, air density of 1.225 kg / m3, perform aerodynamic analysis on the wing and record its lift coefficient;

[0136] S4.3. The lift coefficient data for different aspect ratios were reanalyzed and plotted as curves. The wing analysis using the multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+ had a rendering ratio of 3. These curves were also plotted and compared in the graph. The results are as follows: Figure 7 As shown;

[0137] According to step S5, the specific steps for mathematically modeling the variable-sweep wing aircraft and mathematically abstracting the corresponding control problem include:

[0138] S5.1, the speed of the fuselage of a variable-sweep wing transmedium aircraft is represented by V. b This indicates that, because the sweep angle of the wing of a variable-sweep wing transmedium aircraft can vary, the wing speed can be expressed as... This indicates that S1 represents the distance from the center of the left wing to the center of gravity of the fuselage O. b The position vector, S2, represents the distance from the center of the left wing to the center of gravity of the fuselage, O. b The position vector, according to the relationship between vectors, can be used to derive the velocity of the position vector. Where V i Let i be the velocity at the center of the wing, and let i take the values ​​1 and 2.

[0139] After obtaining the velocity representation method for the variable-sweep wing cross-medium aircraft, a force analysis is performed. Since the variable-sweep wing cross-medium aircraft is a multi-rigid body, it is necessary to analyze each component separately. The variable-sweep wing cross-medium aircraft is divided into three parts: fuselage, left wing, and right wing. The forces acting on the fuselage include the aerodynamic forces F exerted by the air on the fuselage. areo_o The weight G of the fuselage o The thrust T of the variable-sweep wing transcontinental aircraft and the connection force F between the left wing and the fuselage. 1_o and the connection force F between the right wing and the fuselage 2_o The forces acting on the left wing include the aerodynamic force F exerted by the air on the left wing. areo_1 The weight G1 of the left wing and the connecting force F between the fuselage and the left wing. o_1 The forces acting on the right wing include the aerodynamic force F exerted by the air on the right wing. areo_2 The weight G2 of the left wing and the connecting force F of the fuselage to the left wing. o_2 .

[0140] The dynamic equations of the rigid bodies in a variable-sweep wing transmedium aircraft can be expressed in the following form:

[0141]

[0142] Where m0, m1, and m2 are the masses of the fuselage, left wing, and right wing, respectively. Combining the above three equations, we can obtain the overall dynamic equation of the variable-sweep wing transmedium aircraft as follows: Further simplification of the expression yields...

[0143] Will Defined as additional force right The analysis is the same, so we only need to... The derivation is straightforward: S1 = S x ·i+S y ·j+S z ·k, where S x S y S z Let S1 be the component of each coordinate axis in the coordinate system, i, j, and k be the unit vectors of each coordinate axis, and Ω = [ω]. x ,ω y ,ω z ] T Then the velocity expression for the left wing is: in Let S1 be the unit vector. It can be represented as achievable

[0144] In obtaining After the expression, for To conduct analysis, in speed along the wing unit vector, because The expression is too long, so it is represented as a vector: Will The two items can be combined to obtain If we only consider the longitudinal model of the aircraft, then we have S x1 =S x2 S y1 =-S y2 S z1 =S z2 ω x =ω z =0, where subscript 1 represents the left wing and subscript 2 represents the right wing, ultimately yielding

[0145]

[0146] S5.2 Analysis of the moment of a variable-sweep wing transmedia aircraft. First, we analyze the wing of the variable-sweep wing transmedia aircraft, with the wing rotating around O... b The angular momentum is Differentiating the angular momentum of the wing, we get:

[0147] The derivative of the angular momentum can also be expressed in the following format:

[0148] Based on the two equations, we can conclude that:

[0149]

[0150] The moment of a variable-sweep wing transmedium aircraft can be expressed as: Where H O M represents the momentum of the aircraft fuselage. Gi Represents the torque caused by the left and right wings, where It can be represented as:

[0151] Where θ represents the pitch angle of the variable-sweep wing transmedium aircraft, M SG This represents the total torque exerted by the left and right wings of a variable-sweep wing transmedium aircraft on the aircraft along the y-axis.

[0152] S5.3. Based on the forces and moments acting on the aircraft, the longitudinal forces and moments acting on the aircraft are derived to obtain the longitudinal dynamic equations of the aircraft. The specific steps are as follows:

[0153] The longitudinal forces on the variable-sweep wing transmedium aircraft are obtained as follows:

[0154]

[0155] The longitudinal moment of a variable-sweep wing transmedium aircraft is:

[0156]

[0157] Where u represents the velocity of the aircraft along the x-axis, and w represents the velocity of the aircraft along the z-axis; the forces and torques in the longitudinal direction can also be expressed in the following forms:

[0158]

[0159] M z =M za +(-S x cosγ+S y sinγ)g

[0160] Where M zaThe aerodynamic forces acting on the aircraft can be represented by the relationships between the aircraft's angles and velocities. By combining these two methods of expressing forces and moments, the following longitudinal equations for the aircraft can be obtained:

[0161]

[0162] Among them, F Ix F Iz M Iy The representation of is as follows:

[0163]

[0164] S5.4 The variable-sweep wing cross-medium aircraft exhibits a large pitch angle and unstable attitude after ejection from the water. Therefore, attitude control is required to ensure the aircraft can enter the cruise or climb phase with a stable attitude. To address this issue, a controller needs to be designed to control the elevators to rapidly stabilize the pitch angle, and another controller needs to be designed to control the thrust so that the aircraft's speed matches its current attitude.

[0165] In the controller design, the system is divided into an inner loop and an outer loop. The outer loop is the speed loop, using speed as feedback to control speed with thrust, thereby indirectly controlling the angle of attack. The inner loop is the angle loop, using pitch angle as feedback to control pitch angle with the elevator. The speed loop is... The pitch angle loop is:

[0166] Where d1 and d2 are external disturbances, b0 is a coefficient derived empirically, and δ e For elevator deflection, the definitions of the other coefficients are as follows:

[0167]

[0168] The variable-sweep wing cross-medium aircraft has a large pitch angle after emerging from the water, requiring a controller to track the target pitch angle θ. d To enable the variable-sweep wing cross-medium aircraft to track the target angle of attack α d By balancing, the target velocity V corresponding to the angle of attack can be obtained. d The controller is designed to enable the variable-sweep wing cross-medium aircraft to track the target velocity V. d .

[0169] According to step S6, an extended state observer (ESO) is designed to observe the disturbances and nonlinearities in the model, and a controller is designed using backstepping to make the pitch angle track the target θ. d To make the speed track the target speed V d The specific steps are as follows:

[0170] S6.1, Targeting ESO1 is designed to perform real-time observation of the f1+d1 disturbance term and the nonlinear term in this equation. The design form of ESO1 is as follows:

[0171]

[0172] Where z1 is used to estimate V, z2 is used to estimate f1+d1, and β 01 The value is 2000, β 02 The value is 1200.

[0173] S6.2, Targeting ESO2 is designed to address the f2+d2+(b-b0)δ in the equation. e The disturbance and nonlinear terms are observed in real time. The design of ESO2 is as follows:

[0174]

[0175] Where z3 is used to estimate q, and z4 is used to estimate f2+d2+(b-b0)δ e ,β 03 The value is 2100, β 04 The value is 1200.

[0176] S6.3, Design a controller using the backstepping method to make V track the target V. d : via e1=VV d Design Lyapunov functions The thrust controller T of the outer loop is obtained by differentiating V1. The specific steps are as follows:

[0177] Design Lyapunov functions Taking the derivative, we get:

[0178]

[0179] The term f1+d1 can be given by the output z2 of the extended state observer (ESO), and the controller can be designed in the following form:

[0180]

[0181] Where ω1 = f1 + d1, which is given by the output z2 of the extended state observer (ESO), and the parameter k1 is set to 20.

[0182] S6.4, Design error e2=θ-θ d e3 = qq f,vir e4 = q f,vir -qvir Design Lyapunov functions The intermediate controller q is obtained by differentiating V2. vir And the obtained intermediate controller q vir q is obtained through a filter. f,vir Design Lyapunov functions The elevator controller δ is obtained by differentiating V3. e The specific steps are as follows:

[0183] S6.4.1 Design Lyapunov functions Differentiating V2, we get:

[0184]

[0185] Among them, the intermediate controller q vir It can be designed as At this point, the Lyapunov function is

[0186] S6.4.2 Design Lyapunov functions Differentiating V3, we get:

[0187]

[0188] To simplify the expression, ω is used. d Replace f2+d2+bδ e -b0δ e The controller can be designed as follows: Therefore, the controller design for the intermediate controller and the elevator is as follows:

[0189]

[0190] Parameter k2 is set to 10, and b0 is set to 4. The final control effect is as follows: Figures 8-13 As shown, the attitude of a variable-sweep wing transmedium aircraft can be stabilized rapidly, laying the foundation for subsequent climb and cruise.

[0191] This invention employs a collaborative aerodynamic analysis method combining multiphysics simulation and computational fluid dynamics (CFD) software STAR-CCM+ with open-source aerodynamic analysis software XFLRA5 to perform aerodynamic analysis on the main components of a variable-sweep wing aircraft, thereby significantly improving the efficiency of aerodynamic analysis. After aerodynamic analysis and verification, the variable-sweep wing aircraft is mathematically modeled, and the required control problem is mathematically abstracted. For the mathematical problem abstracted in step S5, extended state observers ESO1 and ESO2 are designed to observe disturbances and nonlinear terms in the system. Based on this, a controller is designed using the backstepping method to enable the variable-sweep wing cross-medium aircraft to track the target pitch angle, thus allowing the aircraft to quickly stabilize its attitude after exiting the water and enter climb or cruise states. This method has significant research value for the study of variable-sweep wing cross-medium aircraft.

Claims

1. A method for rapid analysis of longitudinal aerodynamic forces and control of attitude stabilization after water exit for a variable-sweep wing transmedium aircraft, characterized in that, Includes the following steps: S1. Modeling and Aerodynamic Analysis of the Variable-Sweep Wing Transmedium Aircraft: The wing of the variable-sweep wing transmedium aircraft is modeled in the 3D modeling software SOLIDWORKS, and the aerodynamic analysis of the wing of the variable-sweep wing transmedium aircraft is performed using the multiphysics simulation and computational fluid dynamics software STAR-CCM+. S2. Variable-sweep wing cross-medium aircraft fuselage modeling and aerodynamic analysis stage: The fuselage of the variable-sweep wing cross-medium aircraft is modeled in the open-source aerodynamic analysis software XFLR5, and a rapid aerodynamic analysis of the fuselage of the variable-sweep wing cross-medium aircraft is performed. S3. Aerodynamic analysis of elevator of variable-sweep wing cross-medium aircraft: Select the corresponding elevator airfoil in the open-source aerodynamic analysis software XFLR5 and perform rapid aerodynamic analysis of the elevator of variable-sweep wing cross-medium aircraft. S4. Aerodynamic Analysis and Verification Phase: The aerodynamic analysis of the wing was performed using the open-source aerodynamic analysis software XFLR5, and the results were compared and verified with the aerodynamic analysis of the wing in the multiphysics simulation and computational fluid dynamics software STAR-CCM+. S5. Mathematical Model Establishment and Control Problem Abstraction Stage for Variable-Sweep Wing Trans-medium Aircraft: This stage involves establishing a mathematical model of the variable-sweep wing trans-medium aircraft and mathematically abstracting its control problem. Specifically, this includes: S5.

1. Based on the velocity, angular velocity, and static moment of the variable-sweep wing cross-medium aircraft, perform a force analysis on the variable-sweep wing cross-medium aircraft and analyze its angular momentum. S5.

2. Calculate the forces and moments of the variable-sweep wing transmedium aircraft based on the forces and moments of momentum. S5.3 Based on the forces and moments of the variable-sweep wing transmedium aircraft, the longitudinal dynamic equations of the variable-sweep wing transmedium aircraft are obtained; S5.

4. The research problem is mathematically abstracted and simplified to control the speed of a variable-sweep wing cross-medium aircraft through thrust, and control the pitch angle through elevators to keep the attitude of the variable-sweep wing cross-medium aircraft stable. The variable-sweep wing cross-medium aircraft system is divided into an inner loop and an outer loop. The inner loop uses the pitch angle as the feedback quantity, and the outer loop uses the speed as the feedback quantity. The target pitch angle is designed, and the pitch angle is made to track the target pitch angle through the inner loop controller. The target angle of attack is designed, and the target speed is obtained through trim. The speed of the variable-sweep wing cross-medium aircraft is made to track the target speed through the outer loop controller. S6. Controller Design Stage: To address the issues of large pitch angle, poor attitude, and instability of the variable-sweep wing transmedium aircraft after it emerges from the water, an extended state observer (ESO) is designed to observe disturbances and the nonlinearity of the model. Based on this, an inverse stepping controller is designed to control the attitude of the variable-sweep wing transmedium aircraft, enabling the aircraft to stabilize quickly.

2. The method for rapid longitudinal aerodynamic analysis and post-emergence attitude stabilization control of a variable-sweep wing transmedium aircraft according to claim 1, characterized in that, In step S1, the wing of the variable-sweep wing transmedium aircraft is modeled in three dimensions and subjected to aerodynamic analysis. The specific process includes: S1.

1. Perform 3D modeling of the AG08 airfoil using the 3D modeling software SOLIDWORKS; S1.

2. Import the established AG08 airfoil into the multiphysics simulation and computational fluid dynamics software STAR-CCM+, and divide the computational domain of the fluid into the flow field region for simulating airflow, the encrypted region for intensive analysis of the airfoil, and the transition region for intermediate transition processes. S1.

3. Perform relatively coarse meshing on the flow field region and transition region, fine meshing on the wing, and perform surface control on the wing to refine the mesh on the wing surface and set the wing mesh to an overlapping mesh. S1.4 Select the physical model and set the material properties. Use the Spalart-Allmaras turbulence model and ideal gas model. Select three-dimensional space mode for simulation, time is constant, and set the dynamic viscosity and thermal conductivity of the gas. S1.5 Set the simulation conditions for aerodynamics, including velocity, static temperature, turbulence specification, and initial pressure conditions. Set the flow field inlet as a velocity inlet, the other surfaces as symmetry surfaces, the six outer surfaces of the overlapping mesh as overlapping meshes, and the inner surface, which is the wing surface, as a wall surface. S1.

6. By changing the sweep angle and angle of attack of the wing, conduct experimental simulations of the variable sweep wing transmedium aircraft wing and record the aerodynamic parameter data.

3. The method for rapid longitudinal aerodynamic analysis and post-emergence attitude stabilization control of a variable-sweep wing transmedium aircraft according to claim 1, characterized in that, In step S2, the fuselage of the variable-sweep wing transmedium aircraft is modeled and its aerodynamics analyzed. The specific process includes: S2.1 Since the fuselage of the variable-sweep wing transmedium aircraft is a rotating body, it can be considered as a combination of a cylinder and a hemisphere, which is a relatively simple model. Therefore, a simple model of the fuselage is created in the open-source aerodynamic analysis software XFLR5. First, in... Seven key points are determined in the direction to determine the length and cross-section of the variable-sweep wing transmedium aircraft fuselage. The coordinates of five points at each cross-section are selected to determine the cross-sectional shape. S2.2 Since the open-source aerodynamics analysis software XFLR5 requires drawing the wings when performing 3D modeling, the wingspan of the wings is reduced to the fuselage surface, thereby indirectly establishing the fuselage model. S2.

3. Set simulation conditions, set the airflow velocity to... Set the analysis range for the angle of attack to Perform batch aerodynamic analysis on the selected angle of attack; S2.4 Conduct experimental simulations of the fuselage of the variable-sweep wing transmedium aircraft and record the aerodynamic parameter data.

4. A method for rapid longitudinal aerodynamic analysis and post-surface attitude stabilization control of a variable-sweep wing transmedium aircraft according to claim 1, characterized in that, In step S3, the elevator of the variable-sweep wing transmedium aircraft is selected and aerodynamically analyzed using the open-source aerodynamic analysis software XFLR5. The specific process includes: S3.1 In the open-source aerodynamic analysis software XFLR5, select the NACA0012 airfoil and first perform a two-dimensional aerodynamic analysis of the NACA0012 airfoil over a wide range of Reynolds numbers. S3.2 Set the elevator span, set the elevator simulation conditions, and set the simulation range of its Reynolds number and angle of attack; S3.3 Perform aerodynamic analysis on the elevator and record the aerodynamic parameter data; Specifically, in step S4, the open-source aerodynamic analysis software XFLR5 is used to perform aerodynamic analysis of the AG08 airfoil under specific operating conditions, and the aerodynamic analysis of the airfoil is compared and verified with that of the multiphysics simulation and computational fluid dynamics software STAR-CCM+.

5. The method for rapid longitudinal aerodynamic analysis and post-emergence attitude stabilization control of a variable-sweep wing transmedium aircraft according to claim 1, characterized in that, In step S4, the open-source aerodynamic analysis software XFLR5 is used to perform aerodynamic analysis of the AG08 airfoil under specific operating conditions. This analysis is then compared and verified with the aerodynamic analysis of the airfoil performed by the multiphysics simulation and computational fluid dynamics software STAR-CCM+. Specifically, this includes: S4.1 Export the AG08 airfoil coordinate data in Profili2 software; S4.

2. Open the open-source aerodynamics analysis software XFLR5, load the coordinate data file of AG08, set the corresponding Reynolds number and Mach number, set a series of Reynolds numbers, and perform angle of attack range analysis on the AG08 airfoil. Perform two-dimensional aerodynamic analysis and record the aerodynamic data corresponding to the Reynolds number; S4.3 Perform aerodynamic simulations at corresponding Reynolds numbers for wings with different aspect ratios, record the data, and compare the results of the two-dimensional airfoil analysis with the three-dimensional wing analysis results at different aspect ratios with the aerodynamic coefficients in the multiphysics simulation and computational fluid dynamics software STAR-CCM+ with a sweep angle of 0 to verify the reliability of the aerodynamic analysis data in the multiphysics simulation and computational fluid dynamics software STAR-CCM+.

6. A device for rapid analysis of longitudinal aerodynamic forces and attitude stabilization control after water exit for a variable-sweep wing transmedium aircraft, characterized in that, include: The aerodynamic analysis module is used to perform aerodynamic analyses on the wings, fuselage, and elevators of a variable-sweep wing cross-medium aircraft. Specifically, the wing modeling and aerodynamic analysis includes modeling the aircraft's wings in the 3D modeling software SOLIDWORKS and performing aerodynamic analysis on the wings using the multiphysics simulation and computational fluid dynamics software STAR-CCM+. The fuselage modeling and aerodynamic analysis involves modeling the fuselage of the variable-sweep wing cross-medium aircraft in the open-source aerodynamic analysis software XFLR5 and performing rapid aerodynamic analysis on the fuselage. The elevator aerodynamic analysis involves selecting the appropriate elevator airfoil in the open-source aerodynamic analysis software XFLR5 and performing rapid aerodynamic analysis on the elevator. The verification module is used to compare and verify the results of aerodynamic analysis of the wing using the open-source aerodynamic analysis software XFLR5 and the results of multiphysics simulation and aerodynamic analysis of the wing using the computational fluid dynamics software STAR-CCM+. The model establishment and control problem abstraction module is used for the mathematical model establishment and control of variable-sweep wing cross-medium aircraft. This includes establishing the mathematical model of the variable-sweep wing cross-medium aircraft and mathematically abstracting its control problem. Specifically, it performs force analysis on the variable-sweep wing cross-medium aircraft based on its velocity, angular velocity, and static moment, and analyzes its angular momentum. Based on the forces and angular momentum of the variable-sweep wing cross-medium aircraft, it calculates the forces and moments acting on it. The forces and moments acting on the aircraft are used to derive the longitudinal dynamic equations of the variable-sweep wing cross-medium aircraft. The problem is mathematically abstracted and simplified to controlling the speed of the variable-sweep wing cross-medium aircraft through thrust and controlling the pitch angle through elevators to maintain the attitude stability of the variable-sweep wing cross-medium aircraft. The variable-sweep wing cross-medium aircraft system is divided into an inner loop and an outer loop. The pitch angle is used as the feedback quantity in the inner loop and the speed is used as the feedback quantity in the outer loop. The target pitch angle is designed and the pitch angle is made to track the target pitch angle through the inner loop controller. The target angle of attack is designed and the target speed is obtained through trim. The speed of the variable-sweep wing cross-medium aircraft is made to track the target speed through the outer loop controller. The design module is used for controller design. It includes designing an extended state observer (ESO) to observe disturbances and nonlinearities of the model, addressing the problems of large pitch angles, poor attitude, and instability of the variable-sweep wing transmedium aircraft after it emerges from the water. Based on this, an inverse stepping controller is designed to control the attitude of the variable-sweep wing transmedium aircraft, enabling it to stably enter the cruise or climb phase.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the rapid longitudinal aerodynamic analysis and attitude stabilization control method for the variable-sweep wing transmedium aircraft as described in any one of claims 1 to 5.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the rapid longitudinal aerodynamic analysis and attitude stabilization control method for the variable-sweep wing transmedium aircraft as described in any one of claims 1 to 5.

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