Calculation method for predicting ship resistance based on CFD

Abstract

The invention provides a calculation method for predicting the ship resistance based on CFD, and the method comprises the steps: S1, employing a two-phase incompressible RANS as a control equation, which comprises a continuity equation and a momentum equation; S2, processing a free surface through employing a single-phase level set method; S3, enabling a computational domain to be discretized into a series of small units through employing a finite volume method, calculating flow field information, and storing the flow field information at the gravity center of a grid unit; S4, obtaining values of unit surfaces according to the interpolation of the gravity center of the units; S5, solving the sum of the values of the unit surfaces, and obtaining the volume integral of a unit body; S6, carrying out the iterative solving of a pressure speed coupling equation, obtained after discretization, through employing a PISO implicit separation algorithm, wherein the calculation of each time step comprises momentum estimation, pressure solving and speed correction; and finally obtaining a convergent numerical solution. The method employs CFD to calculate and obtain a total resistance coefficient of a ship at a certain operating speed, and calculates and obtains the total resistance of the ship through a simple formula. The method is high in efficiency, is accurate, and is very strong in engineering practicality.

Description

technical field [0001] The invention relates to the technical field of ships, in particular to a calculation method for predicting ship resistance. Background technique [0002] The prediction of resistance performance and the simulation of wave-making conditions for ships sailing in still water have always been a hot research topic in ship shape optimization and design. It is of great significance to improve the accuracy of resistance calculation and to study the internal law of resistance change. The existing research methods include model test, theoretical calculation of potential flow and computational fluid dynamics (CFD) method. [0003] With the improvement of computer computing speed, it is possible to calculate the navigation resistance of ships with highly nonlinear motion characteristics by CFD method. In the CFD calculation method, the methods for numerical simulation of the viscous flow field around the free surface of the hull mainly include direct numerical ...

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Problems solved by technology

[0004] Aiming at the technical problems existing in the existing prior art, the purpose of the present invention is to provide a calculation method based on CFD to predict ship resistance. Compared with the other two methods, it does not pay much attention to the pulsation of turbulent flow. This model is reflected in the time-averaged equation, thus avoiding the problem of large amount of calculation

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