NUMERICAL METHOD FOR SIMULATING WAKE FIELD OF SHIP PROPELLER

摘要

A numerical method for simulating a wake field of a ship propeller. According to characteristics of an incompressible flow, forces in two different forms are added to a momentum equation, so as to improve numerical simulation accuracy of a type of vortex-dominated flow fields. The forces in the two forms are respectively a corkscrew force of a vorticity in a gradient changing direction and a viscous diffusion force of the vorticity in the gradient changing direction. In this method, integral computation of the corkscrew force of the vorticity in the gradient changing direction in a computational grid is converted into flux computation of a force at an edge of the computational grid, so that spatial discretization thereof has a format of high order accuracy. Meanwhile, a source item of the momentum equation keeps the viscous diffusion force of the vorticity in the gradient changing direction, so as to improve the convergence and stability of a numerical solution. Different amplification coefficients are used for the two forces, so that the accuracy of the vorticity can be further maintained, and vortical motion of the wake field of a ship propeller is more accurately simulated.