Submarine sailing resistance calculation method, system and device and storage medium

Abstract

The invention provides a submarine sailing resistance calculation method, system and device and a storage medium, and relates to the technical field of computational fluid mechanics, a real and reliable physical model is constructed firstly, then flow field data is obtained through multi-working-condition CFD simulation, and finally resistance differences under two typical sailing working conditions of a near ice surface and a free water surface are compared and analyzed, so that the sailing resistance of a submarine is calculated. The influence of the ice surface on the hydrodynamic characteristics and navigation performance of the physical model at different diving depths and different navigational speeds is evaluated, and the optimal diving depth and navigational speed range is deduced so as to guide the design and operation optimization of polar region near ice surface navigation. According to the method, the hydrodynamic behavior characteristics of the submarine in the polar region near ice surface limited environment can be accurately revealed, accurate optimization of key design and operation parameters is achieved through high flexibility and repeatability of numerical simulation, a scientific basis is provided for submarine ice region navigation strategy making and power system type selection, and the method has high practical applicability.

Description

Technical Field

[0001] The present application relates to the technical field of computational fluid dynamics, and in particular, to a method, system, device, and storage medium for calculating the navigation resistance of a submarine. Background Art

[0002] As an important platform for ocean scientific exploration and resource investigation, a submarine can stay in areas far from the influence of human activities for a long time, obtain high-precision ocean environment and geological data, and provide reliable support for climate change research, mineral resource assessment, and marine ecological protection. In recent years, with the intensification of global climate change and the growth of polar development needs, the deployment frequency and operation duration of submarines in the shallow polar sea areas have been continuously increasing. Due to the ice thickness in the polar sea areas exceeding three meters, the channels under the ice cover are narrow, and the fluid flow restriction effect is significantly enhanced, resulting in significant changes in the navigation resistance and local pressure distribution, thereby affecting the propulsion efficiency, navigation stability, and control response of the submarine.

[0003] Traditional pool tests are difficult to implement under special working conditions such as in polar regions or near the ice surface due to harsh environments and high risks; while numerical simulation technology, with its high flexibility, low cost, and good adaptability to complex boundary conditions, has become one of the core means for studying the hydrodynamic performance of submarines. Especially during navigation near the ice surface in polar regions, numerical simulation can systematically explore the comprehensive effects of parameters such as speed, diving depth, and ice surface clearance on the flow field disturbance, velocity field distribution, and resistance change. However, existing research has mostly focused on the hydrodynamic characteristics under free surface or deep water conditions, and there has been no systematic research and in-depth analysis on the computational fluid dynamics (CFD) simulation and hydrodynamic characteristics analysis of submarines in the restricted environment near the ice surface. Summary of the Invention

[0004] The purpose of the present application is to provide a method, system, device, and storage medium for calculating the navigation resistance of a submarine in view of the deficiencies in the above technologies.

[0005] To achieve the above purpose, the technical solution adopted by the present application is as follows: The present application provides a method for calculating the navigation resistance of a submarine, including: S1: Establish a physical model of the submarine; S2: Import the physical model into CFD software, and establish a computational domain for defining the navigation area of the physical model. The computational domain includes a computational domain for navigation near the ice surface and a computational domain for free surface navigation; S3: Define the boundary conditions of the computational domain for navigation near the ice surface and the computational domain for free surface navigation, divide the grids within the computational domain for navigation near the ice surface and the computational domain for free surface navigation, configure the numerical calculation conditions of the physical model at different diving depths and different speeds, and set the CFD solution model to solve the flow field data of the fluid around the physical model in different computational domains under different working conditions; S4: Post-process the flow field data to analyze the influence of the ice surface on the navigation performance of the physical model at different submergence depths and different speeds.

[0006] Further, S2 includes: S21: Import the physical model into the CFD software; S22: Set up the geodetic coordinate system, which is used to establish a unified overall reference system; S23: Respectively establish a near-ice navigation calculation domain and a free-surface navigation calculation domain according to the geodetic coordinate system; S24: Respectively set up moving coordinate systems in the near-ice navigation calculation domain and the free-surface navigation calculation domain. The origin of the moving coordinate system is located at the stern of the physical model. The x-axis direction of the moving coordinate system is consistent with the length direction of the physical model. The y-axis direction of the moving coordinate system is consistent with the width direction of the physical model. The z-axis direction of the moving coordinate system is consistent with the height direction of the physical model. The physical model moves along the positive x-axis of the moving coordinate system.

[0007] Further, S3 includes: S31: In the near-ice navigation calculation domain, set the top surface as a no-slip wall surface, set the side surface parallel to the z-axis and on the negative x-axis side as the pressure outlet boundary, and set the remaining surfaces as the velocity inlet boundaries; In the free-surface navigation calculation domain, set the side surface parallel to the z-axis and on the negative x-axis side as the pressure outlet boundary, and set the remaining surfaces as the velocity inlet boundaries; Set the surface of the physical model as a no-slip wall surface; Set the speed range and submergence depth range of the physical model; S32: Divide the grids in the near-ice navigation calculation domain and the free-surface navigation calculation domain, and encrypt the grids in the area around the physical model; S33: Set the CFD solution model, use the incompressible Reynolds-averaged Navier-Stokes equations to describe the fluid motion process around the physical model, and introduce a turbulence model to close the Reynolds stress term to obtain the flow field data; Further, the near-ice navigation calculation domain is a cuboid. The size of the near-ice navigation calculation domain along the x-axis direction is 8.5L. The size of the near-ice navigation calculation domain along the y-axis direction is 1.5L. The size of the near-ice navigation calculation domain along the z-axis direction is 3L; The free-surface navigation calculation domain is a cuboid. The size of the free-surface navigation calculation domain along the x-axis direction is 8.5L. The size of the free-surface navigation calculation domain along the y-axis direction is 1.5L. The size of the free-surface navigation calculation domain along the z-axis direction is 5L, where L is the length of the physical model.

[0008] Further, in S31, in the near-ice surface navigation calculation domain and the free surface navigation calculation domain, the two side surfaces parallel to the x-axis are set as symmetric boundaries.

[0009] Further, in S31, the speed range of the physical model is set to 4 to 12 kn, and the submerged depths of the physical model are set to 1.5D, 2.5D, 3.5D, and 4.5D respectively, where D is the maximum width of the physical model.

[0010] Further, S31 further includes: setting the distance between the stern of the physical model and the pressure outlet boundary to 5.5L.

[0011] Further, S4 includes: post-processing the flow field data, extracting the total resistance coefficient, frictional resistance coefficient, pressure resistance coefficient of the physical model, and the distribution of the surface pressure coefficient of the physical model, and analyzing the influence of the ice surface on the navigation performance of the physical model at different submerged depths and different speeds.

[0012] This application also provides a calculation system for the navigation resistance of a submarine, including: A model import module for establishing a physical model of the submarine, importing the physical model into CFD software, and establishing a calculation domain, which includes a near-ice surface navigation calculation domain and a free surface navigation calculation domain; A numerical calculation module for defining boundary conditions and dividing grids; configuring the numerical calculation conditions of the physical model at different submerged depths and different speeds, and setting the CFD solution model to solve the flow field data of the fluid around the physical model in different calculation domains under different working conditions; A result export module for post-processing the flow field data and analyzing the influence of the ice surface on the navigation performance of the physical model at different submerged depths and different speeds.

[0013] This application also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. The computer program is loaded and executed by the processor to implement any one of the above methods.

[0014] This application also provides a storage medium with a computer program stored thereon. The computer program is loaded and executed by the processor to implement any one of the above methods.

[0015] The beneficial effects of this application include: The present application provides a method for calculating the navigation resistance of a submarine. By first constructing a real and reliable physical model, then obtaining flow field data through CFD simulations under multiple working conditions, and finally comparing and analyzing the resistance differences between two typical navigation conditions, namely near-ice surface and free water surface, to evaluate the influence of the ice surface on the hydrodynamic characteristics and navigation performance of the physical model at different submergence depths and different speeds, and thereby deriving the optimal submergence depth and speed range to guide the design and operation optimization of polar near-ice surface navigation. This method can accurately reveal the hydrodynamic behavior characteristics of submarines in the restricted environment of polar near-ice surface. Through the high flexibility and repeatability of numerical simulation, it realizes the precise optimization of key design and operation parameters, provides a scientific basis for formulating submarine ice area navigation strategies and selecting power systems, and has strong practical applicability. At the same time, this method also provides a reference analysis process and parameter selection basis for subsequent related numerical simulation studies. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the present application, the accompanying drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a flowchart of a method for calculating the navigation resistance of a submarine provided by the present application; Figure 2 It is a schematic diagram of a submarine physical model provided by the present application; Figure 3 It is a schematic diagram of a near-ice surface navigation calculation domain provided by the present application; Figure 4 It is a schematic diagram of a free water surface navigation calculation domain provided by the present application; Figure 5 It is a schematic diagram of the mesh division on the surface of a submarine physical model provided by the present application; Figure 6 It is a schematic diagram of the mesh division of the midship section of a submarine physical model provided by the present application; Figure 7 It is a distribution diagram of the pressure coefficient of the upper edge line of the midship section of a submarine physical model at different submergence depths within the near-ice surface navigation calculation domain; Figure 8 It is a distribution diagram of the pressure coefficient of the upper edge line of the midship section of a submarine physical model at different submergence depths within the free water surface navigation calculation domain; Figure 9 It is a velocity contour map of the fluid around the midship section of a submarine physical model at different speeds. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To make the objectives, technical solutions and advantages of this application clearer, the following will clearly and completely describe the technical solutions in this application in combination with the accompanying drawings in this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all the embodiments. Components of this application that are usually described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0019] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of this application that is claimed, but merely represents the selected embodiments of this application. It should be noted that, without conflict, the various features in the embodiments of this application can be combined with each other, and the combined embodiments are still within the protection scope of this application.

[0020] It should be noted that: similar reference numerals and letters denote similar items in the following accompanying drawings. Therefore, once an item is defined in one accompanying drawing, it does not need to be further defined and explained in subsequent accompanying drawings.

[0021] In the description of this application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the products of this application are habitually placed during use. It is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to this application. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions, and cannot be understood as indicating or implying relative importance.

[0022] In addition, terms such as "horizontal" and "vertical" do not mean that the components are required to be absolutely horizontal or hanging vertically, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0023] In the description of this application, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0024] The following will detail the technical solutions of this application with specific embodiments.

[0025] This application provides a method for calculating the navigation resistance of a submarine, as Figure 1 shown, including: S1: Establish a physical model of the submarine. The physical model should not only completely depict the streamline shape of the hull, the rudder surface and external accessories, but also consider details such as ice edge interference and rudder stock of the steering gear to ensure that the physical model can truly reflect the influence of the cabin body and local protrusions on the surrounding flow field during simulation.

[0026] Further, S1 includes: S11: Collect the geometric dimension data of the submarine through methods such as direct measurement.

[0027] S12: Use 3D modeling software (such as SolidWorks) to establish a physical model of the submarine according to the geometric dimension data of the submarine. In this embodiment, taking the of revolution (Suboff) submarine as an example, a physical model is established, and the ratio of the physical model to the actual size of the submarine is 1:24. As Figure 2 shown, the length of the physical model of the Suboff submarine is 4.356 m, the maximum width (which can also be called the maximum diameter in the Suboff submarine) is 0.508 m, and the height of the conning tower is 0.206 m.

[0028] S2: Import the physical model into CFD software and establish a computational domain for defining the navigation area of the physical model. The computational domain includes a near-ice surface navigation computational domain and a free surface navigation computational domain.

[0029] Further, S2 includes: S21: Import the physical model established in S1 into CFD software.

[0030] S22: Set up a geodetic coordinate system, which is used to establish a unified overall reference system.

[0031] S23: Respectively establish a near-ice surface navigation computational domain and a free surface navigation computational domain according to the geodetic coordinate system. Set the top surface of the near-ice surface navigation computational domain as the bottom surface of the ice layer to simulate two scenarios of restricted channel flow at the bottom of the ice layer and free surface flow respectively.

[0032] S24: To accurately simulate the movement of the physical model in the two computational domains, moving coordinate systems are respectively set up in the computational domain for navigation near the ice surface and the computational domain for navigation on the free surface. The origin of the moving coordinate system is located at the center of the stern of the physical model. The x-axis direction of the moving coordinate system is consistent with the length direction of the physical model, the y-axis direction of the moving coordinate system is consistent with the width direction of the physical model, and the z-axis direction of the moving coordinate system is consistent with the height direction of the physical model. The physical model moves in the positive x-axis direction of the moving coordinate system. Through the moving coordinate system, the translation of the physical model in the positive X-axis direction (or small pitch and yaw around the origin of the moving coordinate system) is clearly mapped into the global geodetic coordinate system so that the subsequent solver can correctly process the flow field data and boundary conditions.

[0033] Further, as Figure 3 and Figure 4 shown, the computational domain for navigation near the ice surface is a cuboid. The dimension of the computational domain for navigation near the ice surface in the x-axis direction is 8.5L, the dimension in the y-axis direction is 1.5L, and the dimension in the z-axis direction is 3L. The computational domain for navigation on the free surface is a cuboid. The dimension of the computational domain for navigation on the free surface in the x-axis direction is 8.5L, the dimension in the y-axis direction is 1.5L, and the dimension in the z-axis direction is 5L, where L is the length of the physical model. In this embodiment, L = 4.356 m.

[0034] S3: Define the boundary conditions for the computational domain for navigation near the ice surface and the computational domain for navigation on the free surface, divide the grids in the computational domain for navigation near the ice surface and the computational domain for navigation on the free surface, configure the numerical calculation conditions of the physical model at different submergence depths and different speeds, and set the CFD solution model to solve the flow field data of the fluid around the physical model in different computational domains under different working conditions. It should be noted that the submergence depth is the vertical distance from the center of gravity of the physical model to the top surface of the computational domain for navigation near the ice surface or the computational domain for navigation on the free surface.

[0035] Further, S3 includes: S31: In the two working conditions of near the ice surface and on the free surface, first, the boundary conditions need to be clarified in their respective computational domains to truly reproduce the submarine navigation environment and effectively control the calculation scale. As Figure 3 and Figure 4As shown in the figure, in the near-ice surface navigation calculation domain, the top surface of the cuboid is set as a no-slip wall surface, the side surface of the cuboid parallel to the z-axis and located on the negative x-axis side (the side facing the oncoming flow direction) is set as a pressure outlet boundary, and the remaining surfaces of the cuboid are set as velocity inlet boundaries. In the free-surface navigation calculation domain, the side surface of the cuboid parallel to the z-axis and located on the negative x-axis side (the side facing the oncoming flow direction) is set as a pressure outlet boundary, and the remaining surfaces of the cuboid are set as velocity inlet boundaries. In both calculation domains, the surface of the physical model is set as a no-slip wall surface. In the near-ice surface navigation calculation domain and the free-surface navigation calculation domain, the two side surfaces parallel to the x-axis are set as symmetric boundaries to reduce the number of grids and the computational workload. To ensure the comparability and stability of the results, the distance between the bow of the physical model and the boundary on the oncoming flow side is set to 2L, the distance between the stern of the physical model and the pressure outlet boundary is set to 5.5L, the speed range of the physical model is set to 4 to 12 kn, and the submergence depths of the physical model are set to 1.5D, 2.5D, 3.5D, and 4.5D respectively, where D is the maximum width of the physical model. In this embodiment, D = 0.508 m.

[0036] S32: After the boundary conditions are defined, the grid generation can be carried out for the two calculation domains. As shown in Figure 5 and Figure 6 the figure, local refinement is implemented near the surface of the physical model and in the wake region, and the grid resolution in the boundary layer and the vortex shedding region is refined; a coarser grid can be used in the far field region to reduce the overall number of elements. S33: After the grid generation is completed, the CFD solution model is set. The incompressible Reynolds-averaged Navier-Stokes equations are used as the basic fluid equations to describe the fluid motion process around the physical model, and an appropriate turbulence model is introduced to close the Reynolds stress terms, so as to balance the capture of high Reynolds number flow characteristics and the solution stability. The choice of a steady-state or unsteady-state solver depends on the dynamic response requirements of the research objective, ensuring that convergent and reliable flow field data results can be obtained at different submergence depths and speeds.

[0037] Among them, the specific expression of the incompressible Reynolds-averaged Navier-Stokes equations is:

[0038] In the formula: ρ represents the density of the fluid, t represents time, p represents pressure, u represents the velocity vector, u i represents the component of the velocity vector, represents the position along the corresponding velocity component direction, F i represents the body force, τxi , τ yi , τ zi respectively represent the viscous stress components in the three directions of the x-axis, y-axis, and z-axis.

[0039] Then, a turbulence model is introduced to close the above equations, and thus the above system of equations is solved. In this embodiment, the turbulence model is selected as SST k - model.

[0040] In the SST k - model, for k , the modeling transport equation is:

[0041] In the formula, ρ ρ represents the density of air, k k represents the turbulent kinetic energy, ω ε represents the specific dissipation rate, and represent the effective diffusivities of k and ω , x j x represents the spatial coordinate, G k Gk represents the turbulent kinetic energy generated due to the mean velocity gradient, Y k and Y ω respectively represent k and ω dissipation terms, D k and D ω respectively represent k and ω cross-diffusion terms, G ω Gb represents the generation term of ω , G ω Y represents indirectly enhancing k the dissipation rate of.

[0042] The time step is set to 0.005 s, and the calculation is carried out through CFD software. The solution residuals of the continuity equation and the momentum equation are both less than 10 -4 , meeting the usual convergence criteria. By verifying the grid independence, the appropriate number of grids is determined, ensuring the calculation accuracy and efficiency. In addition, comparing the calculation results of this application with the experimental results, the error is less than 5%, indicating that this numerical method can better estimate the actual resistance of the submarine and has high accuracy and engineering applicability.

[0043] By setting the navigation conditions of the physical model at different submergence depths (the submergence depths are 1.5D, 2.5D, 3.5D, and 4.5D respectively) and different ship speeds (4 to 12 kn) in the CFD software, the flow field data of the physical model under ice surface restricted conditions and free water surface conditions can be solved.

[0044] S4: Post-process the flow field data to analyze the influence of the ice surface on the navigation performance of the physical model at different submergence depths and different ship speeds.

[0045] Through post-processing of the flow field data (such as correction or fitting), the total resistance coefficient, friction resistance coefficient, and pressure difference resistance coefficient of the physical model under various conditions can be systematically extracted, as well as the distribution of the surface pressure coefficient of the physical model and the velocity contour map of the fluid around the longitudinal section of the hull, obtaining the calculated numerical results of the physical model under different submergence depths and ship speed conditions.

[0046] Figure 7 and Figure 8 are the distribution diagrams of the pressure coefficient of the upper edge line of the mid-longitudinal section (that is, the section cut along the xoz plane) of the submarine physical model at different submergence depths when the ship speed is 6 kn in the navigation calculation domain near the ice surface and the free water surface navigation calculation domain. As Figure 7 and Figure 8 shown, when navigating near the ice surface and on the free water surface, the distribution law of the surface pressure coefficient of the hull is almost the same, and the pressure coefficient increases uniformly with the increase of the submergence depth. The most obvious change in the surface pressure coefficient appears at the position where the submarine hull shape changes, especially around the conning tower and the tail rudder. When navigating near the ice surface, the surface pressure coefficient near the tail fin is significantly lower than that on the free water surface. In addition, when navigating near the ice surface, there are significant changes in the surface pressure coefficient at the trailing edge of the sail and the tail rudder wing. Therefore, when navigating near the ice surface and on the free water surface, the distribution trend of the surface pressure coefficient corresponding to different submergence depths of the submarine at the same ship speed is the same, but the overall value increases with the increase of the submergence depth.

[0047] Figure 9 is the velocity contour map of the fluid around the mid-longitudinal section of the submarine physical model at different ship speeds when the submergence depth is 2.5D. Among them, A, B, C, and D are the velocity contour maps of the fluid at submergence depth 2.5D and ship speeds of 4 kn, 6 kn, 8 kn, and 10 kn respectively in the navigation calculation domain near the ice surface; E, F, G, and H are the velocity contour maps of the fluid at submergence depth 2.5D and ship speeds of 4 kn, 6 kn, 8 kn, and 10 kn respectively in the free water surface navigation calculation domain. As Figure 9As shown, under the action of the ice surface, the velocity field distributions at the bow and stern of the submarine are asymmetric. Low-speed regions and high-pressure regions appear around the bow, stern rudder, and the front and rear of the conning tower. The flow velocity at the trailing edge of the conning tower decreases significantly. Under the navigation conditions of the free water surface, the asymmetry of the flow velocity distribution is weaker than that near the ice surface, and a low-speed recirculation region is formed at the stern. As the distance from the stern increases, the area of this low-speed region gradually decreases.

[0048] Generally speaking, by comparing and analyzing the numerical results in the near-ice surface and free water surface scenarios, the influence of ice surface constraints on the boundary layer thickness, flow separation position, and local acceleration region can be quantified, and the influence law of the ice surface on the submarine flow field disturbance and drag coefficient can be accurately predicted. Furthermore, it can reveal how different combinations of diving depths and speeds change the drag composition and energy loss, which is relatively efficient and accurate. Based on these results, this method can clearly recommend the optimal diving depth - speed range that can both maintain the propulsion efficiency and take into account the navigation stability during polar near-ice surface navigation, providing a scientific basis for submarine hull shape improvement, power system selection, and navigation strategy optimization, and can also significantly reduce the risks and costs of on-site tests, with strong practical applicability.

[0049] This application also provides a calculation system for submarine navigation resistance, including: A model import module, used to establish a physical model of the submarine, import the physical model into CFD software, and establish a calculation domain, where the calculation domain includes a near-ice surface navigation calculation domain and a free water surface navigation calculation domain; A numerical calculation module, used to define boundary conditions and divide grids; configure the numerical calculation conditions of the physical model at different diving depths and different speeds, and set the CFD solution model to solve the flow field data of the fluid around the physical model in different calculation domains under different working conditions; A result export module, used to post-process the flow field data and analyze the influence of the ice surface on the navigation performance of the physical model at different diving depths and different speeds.

[0050] This application also provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor. The computer program is loaded and executed by the processor to implement the method of any of the above.

[0051] This application also provides a storage medium, on which a computer program is stored. The computer program is loaded and executed by the processor to implement the method of any of the above.

[0052] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. A method for calculating the navigation resistance of a submarine, characterized in that, Including: S1: Establish a physical model of a submarine; S2: Import the physical model into CFD software and establish a computational domain for defining the navigation area of the physical model. The computational domain includes a near-ice surface navigation computational domain and a free surface navigation computational domain; S3: Define the boundary conditions of the near-ice surface navigation computational domain and the free surface navigation computational domain, divide grids in the near-ice surface navigation computational domain and the free surface navigation computational domain, configure the numerical calculation conditions of the physical model at different submergence depths and different speeds, and set a CFD solution model to solve the flow field data of the fluid around the physical model in different computational domains under different working conditions; S4: Post-process the flow field data and analyze the influence of the ice surface on the navigation performance of the physical model at different submergence depths and different speeds.

2. The method according to claim 1, wherein The S2 includes: S21: Import the physical model into CFD software; S22: Set a geodetic coordinate system, which is used to establish a unified overall reference system; S23: Respectively establish the near-ice surface navigation computational domain and the free surface navigation computational domain according to the geodetic coordinate system; S24: Respectively set a moving coordinate system in the near-ice surface navigation computational domain and the free surface navigation computational domain. The origin of the moving coordinate system is located at the stern of the physical model. The x-axis direction of the moving coordinate system is consistent with the length direction of the physical model. The y-axis direction of the moving coordinate system is consistent with the width direction of the physical model. The z-axis direction of the moving coordinate system is consistent with the height direction of the physical model. The physical model moves in the positive x-axis direction of the moving coordinate system.

3. The method according to claim 2, wherein The S3 includes: S31: In the near-ice surface navigation computational domain, set the top surface as a no-slip wall surface, set a side surface parallel to the z-axis and on the negative x-axis side as a pressure outlet boundary, and set the remaining surfaces as velocity inlet boundaries; In the free surface navigation computational domain, set a side surface parallel to the z-axis and on the negative x-axis side as a pressure outlet boundary, and set the remaining surfaces as velocity inlet boundaries; Set the surface of the physical model as a no-slip wall surface; Set the speed range and submergence depth range of the physical model; S32: Divide grids in the near-ice surface navigation computational domain and the free surface navigation computational domain, and encrypt the grids in the area around the physical model; S33: Set a CFD solution model, use the incompressible Reynolds-averaged Navier-Stokes equation to describe the fluid motion process around the physical model, and introduce a turbulence model to close the Reynolds stress term to obtain the flow field data.

4. The method according to claim 2 or 3, characterized in that The near-ice surface navigation computational domain is a cuboid. The size of the near-ice surface navigation computational domain in the x-axis direction is 8.5L. The size of the near-ice surface navigation computational domain in the y-axis direction is 1.5L. The size of the near-ice surface navigation computational domain in the z-axis direction is 3L; The free surface navigation calculation domain is a cuboid. The dimension of the free surface navigation calculation domain along the x-axis is 8.5L, the dimension along the y-axis is 1.5L, and the dimension along the z-axis is 5L, where L is the length of the physical model.

5. The method according to claim 3, characterized in that, In S31, for the near-ice surface navigation calculation domain and the free surface navigation calculation domain, the two side surfaces parallel to the x-axis are set as symmetric boundaries.

6. The method according to claim 3 or 5, characterized in that, In S31, the speed range of the physical model is set to be 4 to 12 kn, and the submergence depths of the physical model are set to be 1.5D, 2.5D, 3.5D, and 4.5D respectively, where D is the maximum width of the physical model.

7. The method according to claim 3 or 5, characterized in that, S31 further includes: setting the distance between the stern of the physical model and the pressure outlet boundary to be 5.5L, where L is the length of the physical model.

8. A calculation system for the navigation resistance of a submarine, characterized in that, It includes: A model import module, which is used to establish a physical model of a submarine, import the physical model into CFD software, and establish a calculation domain, where the calculation domain includes a near-ice surface navigation calculation domain and a free surface navigation calculation domain; A numerical calculation module, which is used to define boundary conditions, divide grids; configure the numerical calculation conditions of the physical model at different submergence depths and different speeds, and set a CFD solution model to solve the flow field data of the fluid around the physical model in different calculation domains under different working conditions; A result export module, which is used to post-process the flow field data and analyze the influence of the ice surface on the navigation performance of the physical model at different submergence depths and different speeds.

9. An electronic device, characterized in that, It includes a memory, a processor, and a computer program stored on the memory and executable on the processor. The computer program is loaded and executed by the processor to implement the method according to any one of claims 1 to 7.

10. A storage medium, characterized in that, A computer program is stored on the storage medium and is loaded and executed by the processor to implement the method according to any one of claims 1 to 7.

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