A method for analyzing mutual interference of flow fields of a variable configuration underwater vehicle

Abstract

The present application relates to the field of underwater vehicle flow field analysis, and discloses a variable reconstruction underwater vehicle flow field mutual interference analysis method, comprising: modeling a single underwater vehicle; based on the single underwater vehicle, constructing a variable reconstruction underwater vehicle; converting the variable reconstruction process into a series of transient processes parameterized by the axial spacing between the head end face and the tail end face of adjacent single underwater vehicles; building a fluid simulation calculation framework, and batch calculating the fluid dynamic parameters of different parts of the variable reconstruction underwater vehicle under different axial spacings corresponding to each transient process; based on the variation law of the fluid dynamic parameters with the axial spacing, determining a characteristic spacing from the axial spacing; using the velocity nephogram and the pressure nephogram, and combining the characteristic spacing and the fluid dynamic parameters of different parts of the variable reconstruction underwater vehicle, the flow field mutual interference is analyzed. The present application effectively reduces the calculation cost and improves the efficiency of flow field analysis.

Description

Technical Field

[0001] This invention relates to the field of underwater vehicle flow field analysis, and more specifically to a method for analyzing mutual interference in the flow field of a variant-reconstructed underwater vehicle. Background Technology

[0002] As a crucial component of marine equipment, unmanned underwater vehicles (UUVs) are widely used in scenarios such as seabed mapping, marine environmental monitoring, marine resource development, and underwater obstacle search and location. Multi-UUV combined operations are also widely employed; reconfiguring multiple individual UUVs into a single UUV assembly through variant conversion can significantly reduce drag, increase range, and facilitate deployment and recovery. However, the flow field during the combination of multiple UUVs is highly complex. Directly performing variant conversion without understanding the flow field development poses serious risks, affecting the success rate and stability of UUV variant conversion. Therefore, it is necessary to analyze the flow field development during the variant conversion process.

[0003] Generally speaking, dynamic processes such as variant reconstruction require simulation calculations using dynamic mesh technology. However, dynamic mesh technology has high requirements for mesh quality, and because the UUV mesh itself is encrypted and has a large number of meshes, it is difficult to divide high-precision dynamic meshes during the variant reconstruction of UUV combinations. This results in very high computational costs and significantly reduced computational efficiency of simulation analysis methods based on dynamic meshes. Summary of the Invention

[0004] The purpose of this invention is to provide a method for analyzing flow field interference in variant reconstructed underwater vehicles, in order to solve the problems of high computational cost and high cost in the existing analysis of flow field interference in variant reconstructed underwater vehicles.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A variant reconstruction method for analyzing flow field interference in underwater vehicles includes:

[0007] Modeling a single underwater vehicle;

[0008] Based on a single underwater vehicle, a variant reconstructed underwater vehicle is constructed; the variant reconstructed process is transformed into a series of transient processes parameterized by the axial spacing between the head and tail faces of adjacent single underwater vehicles.

[0009] A fluid simulation calculation framework was built to perform batch calculations of the hydrodynamic parameters of different parts of the underwater vehicle under different axial spacings corresponding to each transient process;

[0010] Based on the variation law of fluid dynamic parameters with axial spacing, the characteristic spacing is determined from the axial spacing.

[0011] By using velocity and pressure cloud maps, combined with characteristic spacing and variants, the hydrodynamic parameters of different parts of the underwater vehicle are reconstructed for flow field interference analysis.

[0012] Furthermore, modeling of individual underwater vehicles is performed, including:

[0013] Construct a coordinate system in CAD software;

[0014] The head and tail profile curves of a monolithic underwater vehicle are generated using Granville lines, with the diameters of the head and tail end faces being the same.

[0015] Connect the head and tail curves to generate the midsection profile of the monolithic underwater vehicle; draw lines perpendicular to the coordinate system from the center of the head end face and the center of the tail end face respectively. Line segments of the axis, and connect the two line segments with each other. The intersection of the axes generates a rotation section; by rotating and stretching the rotation section, the main body model of the single underwater vehicle is generated.

[0016] Based on the main model, airfoil shape points are generated according to NACA airfoil and imported into CAD software to generate rudder airfoil sections; by stretching the rudder airfoil sections, all-moving rudders are generated, thus completing the modeling of a single underwater vehicle.

[0017] Furthermore, based on a single underwater vehicle, a variant reconstructed underwater vehicle is constructed; the variant reconstruction process is transformed into a series of transient processes parameterized by the axial spacing between the head and tail faces of adjacent single underwater vehicles, including:

[0018] In the coordinate system The single underwater vehicle is moved and copied along the axis. The single underwater vehicle in front is used as the first underwater vehicle, and the other one is used as the second underwater vehicle, resulting in a variant reconstructed underwater vehicle in the initial state. The initial state refers to the state when the axial distance between the tail end face of the first underwater vehicle and the head end face of the second underwater vehicle is zero.

[0019] During the variant reconstruction process of the second underwater vehicle moving relative to the first underwater vehicle, the axial spacing is used to characterize different moments in the variant reconstruction process, thereby temporally differentiating the continuous variant reconstruction process and decomposing it into multiple transient processes.

[0020] Furthermore, a fluid simulation calculation framework is established, including:

[0021] An external flow field computational domain is defined for the variant reconstructed underwater vehicle; the external flow field computational domain is defined as a cylinder with a length of [missing information]. The total length and diameter of the underwater vehicle reconstructed by the variant in the initial state are [value missing]. The maximum cross-sectional diameter of the single-unit underwater vehicle is doubled; the boundary of the external flow field computational domain is set for fluid dynamics calculations: the bottom surface of the cylinder facing the head end face of the first underwater vehicle is taken as the velocity inlet, and the bottom surface of the cylinder facing the tail end face of the second underwater vehicle is taken as the pressure outlet; the side wall of the cylinder is taken as the wall of the external flow field computational domain; whereby... This is the default value;

[0022] Using the axial distance between the tail end face of the first underwater vehicle and the head end face of the second underwater vehicle as the driving parameter, and employing Matlab programming and ANSYS Workbench scripts, the underwater vehicle is automatically reconstructed by generating corresponding variants when the driving parameter is modified.

[0023] Furthermore, batch calculations are performed to reconstruct the hydrodynamic parameters of different parts of the underwater vehicle at different axial spacings corresponding to each transient process, including:

[0024] For each axial spacing, perform the following steps to obtain the corresponding hydrodynamic parameters:

[0025] The computational domain of the variant reconstructed underwater vehicle and the external flow field was meshed using CFD software. The mesh was refined on the variant reconstructed underwater vehicle, and a boundary layer was partitioned for the entire variant reconstructed underwater vehicle.

[0026] The fluid dynamics solver in the CFD software is invoked to calculate the fluid dynamic parameters of the variant reconstructed underwater vehicle corresponding to the current axial spacing under preset solution conditions;

[0027] Start CFD calculation; after the calculation converges, output and record the hydrodynamic parameters of different parts of the variant reconstructed underwater vehicle; the hydrodynamic parameters include drag, lateral force coefficient, lift coefficient, pitching moment coefficient and pressure coefficient.

[0028] Furthermore, the preset solution conditions include: using the SST k-ω turbulence model and the SIMPLEC algorithm with a second-order upwind scheme; the external flow field computational domain wall is a specified shear force wall; all surfaces of the first and second underwater vehicles are non-slip walls; and setting the inlet velocity and the number of iterations.

[0029] Furthermore, based on the variation law of hydrodynamic parameters with axial spacing, the characteristic spacing is determined from the axial spacing, including:

[0030] A line graph is plotted with the axial spacing as the x-axis and the hydrodynamic parameters of different parts of the variant reconstructed underwater vehicle as the y-axis. The changing trend of each hydrodynamic parameter with the axial spacing is obtained, and the axial spacing corresponding to the sudden change of the hydrodynamic parameter or the inflection point of the line graph is identified as the feature spacing.

[0031] Furthermore, using velocity and pressure contour maps, combined with characteristic spacing and variants, the hydrodynamic parameters of different parts of the underwater vehicle are reconstructed for flow field interference analysis, including:

[0032] Extract velocity contour maps and analyze the distribution, size, and location of high-speed and low-speed flow regions in the velocity contour maps to determine the flow state of the fluid at the time corresponding to the characteristic spacing.

[0033] By extracting pressure contour maps and analyzing the distribution, size, and location of high-pressure and low-pressure regions within these maps, and combining this with the definition of fluid dynamic parameters, the reasons for the changes in these parameters are analyzed.

[0034] A terminal device includes a processor, a memory, and a computer program stored in the memory; when the processor executes the computer program, it implements the variant reconstructed underwater vehicle flow field mutual interference analysis method.

[0035] A computer-readable storage medium storing a computer program; when executed by a processor, the computer program implements the variant reconstructed underwater vehicle flow field mutual interference analysis method.

[0036] Compared with the prior art, the present invention has the following technical features:

[0037] This invention addresses the flow field interference analysis problem of variator-reconstructed underwater vehicles (UVVs). It establishes a fluid simulation framework for UVVs, decomposing the dynamic process of variator reconstruction into multiple transient processes with different axial spacings. CFD simulation is used to obtain the variation trends of hydrodynamic parameters at different locations with axial spacing, effectively reducing computational costs. Furthermore, velocity and pressure contour maps can be combined to analyze flow field development and causes. This invention avoids the use of moving meshes, thus significantly reducing computational costs and accelerating flow field analysis. It enables approximate flow field analysis of the variator reconstruction process at a lower cost, which is of great significance for improving the design success rate and stability of variator-reconstructed underwater vehicles. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating the method of the present invention;

[0039] Figure 2 This is a schematic diagram of the axial spacing during the process of constructing a variant to reconstruct an underwater vehicle;

[0040] Figure 3 This is a schematic diagram of the mesh generation of a variant reconstructed underwater vehicle in an embodiment of the present invention;

[0041] Figure 4 This is a line graph drawn based on hydrodynamic parameters and axial spacing in an embodiment of the present invention; in the figure, X represents the variant reconstructed underwater vehicle, X1 represents the first underwater vehicle, and X2 represents the second underwater vehicle; tou1, body1, wei1, and duo1 represent the head, midsection, tail, and all-moving rudder of the first underwater vehicle, respectively; tou2, body2, wei2, and duo2 represent the head, midsection, tail, and all-moving rudder of the second underwater vehicle, respectively.

[0042] Figure 5 This is a pressure cloud map from the simulation results of an embodiment of the present invention; where Static Pressure represents static pressure, and the unit is Pa;

[0043] Figure 6 This is a velocity cloud map from the simulation results of an embodiment of the present invention; where Velocity Magnitude represents the velocity magnitude in m / s. Detailed Implementation

[0044] Existing technologies offer limited understanding of the fluid changes during the docking process of variator-reconstructed underwater vehicles (UVVs), and the fluid interference between the preceding and following UVVs is also poorly understood. However, dynamic meshing technology demands high mesh quality and quantity, making the computational cost of a single dynamic mesh reconstruction simulation very high. Therefore, a detailed study of the variator-reconstruction process is extremely expensive. To address this, this invention provides a flow field mutual interference analysis method for variator-reconstructed UVVs, used to analyze the flow field changes and interaction mechanisms of a variator-reconstructed UVV composed of a first and a second UVV during the reconstruction process. This method discretizes the dynamic reconstruction process using time difference and combines parametric modeling and automated simulation techniques to efficiently and accurately obtain the flow field characteristics during the variator process. See also... Figure 1 The method steps of this invention are as follows:

[0045] Step 1: Model a single underwater vehicle.

[0046] Step 1.1: Construct a coordinate system in CAD software (such as SolidWorks); the line connecting the center of the head end face and the center of the tail end face of the single underwater vehicle is the x-axis, and the direction from the tail end face to the head end face is the positive x-axis direction; the longitudinal symmetry plane of the single underwater vehicle is the xOy plane; the vector direction perpendicular to the xOy plane pointing to the right is the positive z-axis direction, and the vector direction perpendicular to the z-axis and pointing upward in the xOy plane is the positive y-axis direction. The center of the single underwater vehicle is taken as the origin O.

[0047] Step 1.2: Generate the head profile curve A and tail profile curve B of the monolithic underwater vehicle using the Granville profile in CAD software. Head profile curve A uses the rounded head profile curve from the Granville profile, while tail profile curve B uses the pointed tail profile curve from the Granville profile. To ensure variant reconstruction functionality, the diameters of the head and tail end faces must be consistent; both the rounded head and pointed tail profile curves are quadratic polynomial curves.

[0048] Step 1.3: Connect the headline curve A and the tailline curve B to generate the mid-section curve C of the monolithic underwater vehicle; draw line segments D1 and D2 perpendicular to the x-axis from the center of the head end face and the center of the tail end face (i.e., the head and tail endpoints), and connect the intersections of the two line segments D1 and D2 with the x-axis with the connecting line E to generate a closed rotation section of the underwater vehicle; this rotation section is formed by connecting A, C, B, D2, E, and D1 in sequence; by rotating and stretching the rotation section, generate the main body model of the monolithic underwater vehicle.

[0049] Step 1.4: Based on the main model, generate airfoil shape points according to NACA airfoil and import them into CAD software to generate rudder airfoil sections; generate all-moving rudders by stretching the rudder airfoil sections, thereby completing the modeling of a single underwater vehicle (consisting of the main model and all-moving rudders).

[0050] Step 2: Based on the single underwater vehicle, construct a variant reconstructed underwater vehicle; transform the variant reconstructed process into a series of transient processes parameterized by the axial spacing between the head and tail faces of adjacent single underwater vehicles.

[0051] Step 2.1: Move and copy the single underwater vehicle along the x-axis. After copying, use the single underwater vehicle located in front as the first underwater vehicle and the other as the second underwater vehicle, thus obtaining the variant reconstructed underwater vehicle in the initial state; the initial state refers to the axial distance between the tail end face of the first underwater vehicle and the head end face of the second underwater vehicle. The state when it is zero.

[0052] It should be noted that this scheme is described as a variant reconfigurable underwater vehicle containing two individual underwater vehicles, but in actual design, the variant reconfigurable underwater vehicle can contain more individual underwater vehicles.

[0053] Step 2.2, during the variant reconstruction process of the second underwater vehicle moving relative to the first underwater vehicle, with the axial spacing This is used to characterize different moments in the variant reconstruction process, thereby decomposing the continuous variant reconstruction process into multiple transient processes through time difference; that is, each axial spacing in the variant reconstruction process. Corresponding to a discrete time .

[0054] Through the above steps, the dynamic variant reconstruction process is transformed into a series of processes based on axial spacing. A parameterized, static, discrete transient process. Variant reconstruction refers to the process in which the second underwater vehicle and the first underwater vehicle move relative to each other and merge into one.

[0055] Step 3: Build a fluid simulation calculation framework and perform batch calculations of the hydrodynamic parameters of the reconstructed underwater vehicle under different axial spacings.

[0056] The process of building the fluid simulation calculation framework is as follows:

[0057] Step 3.1: Set the external flow field computational domain for the variant reconstructed underwater vehicle; the external flow field computational domain is set as a cylinder, the length of which is N times the total length of the variant reconstructed underwater vehicle in the initial state, and the diameter is N times the maximum cross-sectional diameter of the single underwater vehicle; the boundary of the external flow field computational domain is set by CFD calculation: the bottom surface of the cylinder facing the head end face of the first underwater vehicle is taken as the velocity inlet, and the bottom surface of the cylinder facing the tail end face of the second underwater vehicle is taken as the pressure outlet; the side wall of the cylinder is taken as the wall of the external flow field computational domain; the preset value N is set according to the actual simulation requirements, for example, N=10.

[0058] Step 3.2, adjust the axial distance between the tail end face of the first underwater vehicle and the head end face of the second underwater vehicle. As driving parameters, Matlab programming and ANSYS Workbench scripts are used to implement the control of driving parameters. When making modifications, the corresponding variant is automatically generated to reconstruct the underwater vehicle.

[0059] Step 3.3: Use CFD software (such as ANSYS Workbench simulation management platform) to mesh the computational domain of the variant reconstructed underwater vehicle and the external flow field. Refine the mesh on the variant reconstructed underwater vehicle and perform boundary layer meshing on the entire variant reconstructed underwater vehicle. By limiting the maximum size of the meshes on the first and second underwater vehicles, ensure that the variant reconstructed underwater vehicle is not distorted. The boundary layer meshing should ensure that the dimensionless wall distance is no greater than 10, and the lower the better.

[0060] Step 3.4: Call the fluid dynamics solver in the CFD software to calculate the current axial spacing under preset solution conditions. The corresponding variant reconstructs the hydrodynamic parameters of the underwater vehicle; the preset solution conditions include:

[0061] The SST k-ω turbulence model and the SIMPLEC algorithm with a second-order upwind scheme were adopted. The external flow field computational domain wall was a specified shear force wall (the "shear condition" was set to "specified shear force" in the wall property settings of the CFD software). All surfaces of the first and second underwater vehicles were no-slip walls (the "shear condition" was set to "no slip" in the wall property settings of the CFD software). The inlet velocity and the number of iterations were set.

[0062] Step 3.5: Initiate CFD calculations using CFD software; after convergence, output and record the hydrodynamic parameters of different parts of the variogram-reconstructed underwater vehicle, including: the drag of the variogram-reconstructed underwater vehicle. The resistance of the first underwater vehicle The resistance of the second underwater vehicle And the drag of the first and second underwater vehicles at the head, midsection, tail, and all-moving rudders.

[0063] Step 3.6, change the axial spacing By repeating steps 3.2 to 3.5, a series of different axial spacings can be automatically obtained. The following are the hydrodynamic parameters.

[0064] Step 4: Based on the variation law of fluid dynamic parameters with axial spacing, determine the characteristic spacing from the axial spacing.

[0065] For different axial spacing The fluid dynamic parameters are analyzed as a function of the axial spacing. The variation pattern; based on axial spacing The x-axis represents the hydrodynamic parameters of different parts of the underwater vehicle, reconstructed using variants (including...). , , A line graph was plotted with the drag at the head, midsection, tail, and all-moving rudder of the first and second underwater vehicles as the ordinate, yielding the various hydrodynamic parameters as a function of axial spacing. The changing trend can be used to identify the axial spacing corresponding to sudden changes in fluid dynamic parameters or inflection points in the line graph. As feature spacing .

[0066] It should be noted that, in addition to drag, the above-mentioned hydrodynamic parameters can also be set to other parameters according to simulation requirements, such as lateral force coefficient, lift coefficient, pitching moment coefficient, and pressure coefficient.

[0067] Step 5: Using velocity and pressure cloud maps, combined with characteristic spacing and variants, reconstruct the hydrodynamic parameters of different parts of the underwater vehicle to perform flow field interference analysis.

[0068] Extract velocity contour maps and analyze the distribution, size, and location of high-speed and low-speed flow regions within them to determine the fluid flow at characteristic intervals. The flow state at the corresponding moment;

[0069] Extract pressure contour maps, analyze the distribution, size, and location of high-pressure and low-pressure regions in the pressure contour maps, and combine this with the definition of fluid dynamic parameters to analyze the reasons for the changes in fluid dynamic parameters (fluid dynamic parameters are usually generated by the pressure difference between high and low pressure).

[0070] The determination of high-pressure and low-pressure regions, as well as high-speed and low-speed flow regions, is automatically provided by the CFD software or set by the user.

[0071] Example

[0072] See Figure 2 In one embodiment of this invention, the main model of the monolithic underwater vehicle is selected from the main model of the MK46 vehicle. The fin rudder adopts a cross-shaped all-moving rudder, and the fin rudder shape adopts the NACA0012 airfoil. Modeling is performed using SolidWorks. The monolithic underwater vehicle has a total length of 2500mm, a maximum diameter of 300mm, a rudder span of 100mm, a chord length of 250mm, a bow length of 300mm, and a tail length of 700mm. The mesh generation result of the variant reconstruction of the underwater vehicle in this embodiment is as follows: Figure 3 As shown.

[0073] When discretizing the reconstruction process, the axial spacing The range is from 0 to 1, representing the total length of a single underwater vehicle, i.e., [0, 2500] mm; a total of 11 discrete time points are set. The corresponding axial spacing The corresponding sizes are: 0mm, 50mm, 100mm, 200mm, 300mm, 400mm, 500mm, 1000mm, 1500mm, 2000mm, and 2500mm.

[0074] In the fluid simulation calculation framework, the inlet velocity is set to... The simulation was performed 1000 times; after completion, the flow field interference mechanism was analyzed. The line graph in the simulation results of this embodiment is shown below. Figure 4 As shown; by Figure 4 Analysis shows that the main reason for the mutual disturbance of the flow fields between the first and second underwater vehicles is that the flow fields generated by the tail of the first underwater vehicle and the head of the second underwater vehicle overlap and interfere with each other; Figure 5 and Figure 6 It can be seen that due to the mutual interference of the flow fields, the fluid velocity in the area where the tail of the first underwater vehicle and the head of the second underwater vehicle meet is low, resulting in a high-pressure area. This reduces the pressure difference between the front and rear of the first underwater vehicle and decreases its resistance, while increasing the pressure difference between the front and rear of the second underwater vehicle and increasing its resistance.

[0075] Through simulation, the development and causes of flow fields can be effectively analyzed, thus providing an efficient and convenient analytical tool for the design of variant reconstructed underwater vehicles.

[0076] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A method for analyzing flow field interference in a variant-reconstructed underwater vehicle, characterized in that, include: Modeling a single underwater vehicle; Based on a single underwater vehicle, a variant reconstructed underwater vehicle is constructed; the variant reconstructed process is transformed into a series of transient processes parameterized by the axial spacing between the head and tail faces of adjacent single underwater vehicles. A fluid simulation calculation framework was built to perform batch calculations of the hydrodynamic parameters of different parts of the underwater vehicle under different axial spacings corresponding to each transient process; Based on the variation law of fluid dynamic parameters with axial spacing, the characteristic spacing is determined from the axial spacing. By using velocity and pressure cloud maps, combined with characteristic spacing and variants, the hydrodynamic parameters of different parts of the underwater vehicle are reconstructed for flow field interference analysis.

2. The method for analyzing flow field interference of a variant-reconstructed underwater vehicle according to claim 1, characterized in that, Modeling a single underwater vehicle includes: Construct a coordinate system in CAD software; The head and tail profile curves of a monolithic underwater vehicle are generated using Granville lines, with the diameters of the head and tail end faces being the same. Connect the head and tail curves to generate the midsection profile of the monolithic underwater vehicle; draw lines perpendicular to the coordinate system from the center of the head end face and the center of the tail end face respectively. Line segments of the axis, and connect the two line segments with each other. The intersection of the axes generates a rotation section; by rotating and stretching the rotation section, the main body model of the single underwater vehicle is generated. Based on the main model, airfoil shape points are generated according to NACA airfoil and imported into CAD software to generate rudder airfoil sections; by stretching the rudder airfoil sections, all-moving rudders are generated, thus completing the modeling of a single underwater vehicle.

3. The method for analyzing flow field interference of a variant-reconstructed underwater vehicle according to claim 2, characterized in that, Based on a single-unit underwater vehicle, a variant-reconstructed underwater vehicle is constructed; the variant reconstruction process is transformed into a series of transient processes parameterized by the axial spacing between the head and tail faces of adjacent single-unit underwater vehicles, including: In the coordinate system The single underwater vehicle is moved and copied along the axis. The single underwater vehicle in front is used as the first underwater vehicle, and the other one is used as the second underwater vehicle, resulting in a variant reconstructed underwater vehicle in the initial state. The initial state refers to the state when the axial distance between the tail end face of the first underwater vehicle and the head end face of the second underwater vehicle is zero. During the variant reconstruction process of the second underwater vehicle moving relative to the first underwater vehicle, the axial spacing is used to characterize different moments in the variant reconstruction process, thereby temporally differentiating the continuous variant reconstruction process and decomposing it into multiple transient processes.

4. The method for analyzing flow field interference of a variant-reconstructed underwater vehicle according to claim 3, characterized in that, Establish a fluid simulation calculation framework, including: An external flow field computational domain is defined for the variant reconstructed underwater vehicle; the external flow field computational domain is defined as a cylinder with a length of [missing information]. The total length and diameter of the underwater vehicle reconstructed by the variant in the initial state are [value missing]. The maximum cross-sectional diameter of the single-unit underwater vehicle is doubled; the boundary of the external flow field computational domain is set for fluid dynamics calculations: the bottom surface of the cylinder facing the head end face of the first underwater vehicle is taken as the velocity inlet, and the bottom surface of the cylinder facing the tail end face of the second underwater vehicle is taken as the pressure outlet; the side wall of the cylinder is taken as the wall of the external flow field computational domain; whereby... This is the default value; Using the axial distance between the tail end face of the first underwater vehicle and the head end face of the second underwater vehicle as the driving parameter, and employing Matlab programming and ANSYS Workbench scripts, the underwater vehicle is automatically reconstructed by generating corresponding variants when the driving parameter is modified.

5. The method for analyzing flow field interference of a variant-reconstructed underwater vehicle according to claim 4, characterized in that, Batch calculations were performed to reconstruct the hydrodynamic parameters of different parts of the underwater vehicle at different axial spacings corresponding to each transient process, including: For each axial spacing, perform the following steps to obtain the corresponding hydrodynamic parameters: The computational domain of the variant reconstructed underwater vehicle and the external flow field was meshed using CFD software. The mesh was refined on the variant reconstructed underwater vehicle, and a boundary layer was partitioned for the entire variant reconstructed underwater vehicle. The fluid dynamics solver in the CFD software is invoked to calculate the fluid dynamic parameters of the variant reconstructed underwater vehicle corresponding to the current axial spacing under preset solution conditions; Start CFD calculation; after the calculation converges, output and record the hydrodynamic parameters of different parts of the variant reconstructed underwater vehicle; the hydrodynamic parameters include drag, lateral force coefficient, lift coefficient, pitching moment coefficient and pressure coefficient.

6. The method for analyzing flow field interference of a variant-reconstructed underwater vehicle according to claim 5, characterized in that, The preset solution conditions include: using the SST k-ω turbulence model and the SIMPLEC algorithm with a second-order upwind scheme; the external flow field computational domain wall is a specified shear force wall; all surfaces of the first and second underwater vehicles are non-slip walls; and setting the inlet velocity and the number of iterations.

7. The method for analyzing flow field interference of a variant-reconstructed underwater vehicle according to claim 1, characterized in that, Based on the variation of hydrodynamic parameters with axial spacing, characteristic spacing is determined from the axial spacing, including: A line graph is plotted with the axial spacing as the x-axis and the hydrodynamic parameters of different parts of the variant reconstructed underwater vehicle as the y-axis. The changing trend of each hydrodynamic parameter with the axial spacing is obtained, and the axial spacing corresponding to the sudden change of the hydrodynamic parameter or the inflection point of the line graph is identified as the feature spacing.

8. The method for analyzing flow field interference of a variant-reconstructed underwater vehicle according to claim 1, characterized in that, Using velocity and pressure contour maps, combined with characteristic spacing and variants, hydrodynamic parameters of different parts of the underwater vehicle are reconstructed for flow field interference analysis, including: Extract velocity contour maps and analyze the distribution, size, and location of high-speed and low-speed flow regions in the velocity contour maps to determine the flow state of the fluid at the time corresponding to the characteristic spacing. By extracting pressure contour maps and analyzing the distribution, size, and location of high-pressure and low-pressure regions within these maps, and combining this with the definition of fluid dynamic parameters, the reasons for the changes in these parameters are analyzed.

9. A terminal device, comprising a processor, a memory, and a computer program stored in the memory; characterized in that, When the processor executes a computer program, it implements the variant reconstructed underwater vehicle flow field mutual interference analysis method as described in any one of claims 1-8.

10. A computer-readable storage medium storing a computer program; characterized in that, When the computer program is executed by the processor, it implements the variant of the underwater vehicle flow field mutual interference analysis method as described in any one of claims 1-8.

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