Method for acquiring direct route added mass of underwater vehicle

Abstract

The invention provides a method for obtaining the direct route added mass of an underwater vehicle. The method comprises the steps that A, importing an AUV model; B, carrying out grid division; C, verifying grid independence to obtain a better network; D, performing time step independence verification to obtain a better transient simulation time step; E, importing grids; and F, compiling a UDF program and importing the UDF program into fluent for transient simulation. Different from a traditional CFD method based on dynamic grids, the method does not need to use the dynamic grids, simulates the speed change process of the AUV by changing the fluid speed, monitors a resistance value, and solves the added mass through calculation. According to the method, the calculation precision is ensured, the grid requirement is reduced, and the calculation speed is greatly improved. In order to verify the accuracy of the method, CFD simulation and theoretical calculation are carried out on a standard ellipsoid. The deviation between the obtained added mass value and a theoretical calculation value is smaller than 3%, and it is indicated that in the initial stage of design, the result of calculating the added mass of the AUV with any shape in the direct route direction through the method is reliable.

Description

technical field [0001] The invention belongs to the technical field of ships and ocean engineering, and in particular relates to a method for obtaining the quality of an underwater vehicle's direct flight attachment. Background technique [0002] Autonomous Underwater Vehicle (AUV) is a non-standard equipment commonly used in ocean exploration and surveillance. AUV will customize the shell according to the needs of users, so AUVs have different shapes. In order to better manipulate an AUV, one must first understand its maneuverability in water. Added mass is the hydrodynamic force experienced by an object in unsteady motion in an ideal fluid, and it is one of the parameters of the maneuverability of a submarine. [0003] Methods to obtain the additional quality of non-standard AUV include EFD (Empirical Fluid Dynamics, empirical fluid dynamics), CFD (Computational Fluid Dynamics, computational fluid dynamics), Hess-Smith panel method and underwater experiments. Among them...

AI Technical Summary

Problems solved by technology

The use of dynamic mesh simulation will inevitably cause partial mesh movement and reconstruction, and in order to ensure the accuracy of CFD simulation, the surface mesh size of objects with more complex shapes is often smaller, and the small size mesh limits the unit time step of dynamic mesh simulation. , which reduces the solution speed and cannot quickly solve the additional mass

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