Numerical Analysis of Axisymmetric Supercavitating Flows, Using Boundary Element Method

This paper presents a boundary element method (BEM) formulation for solution of axisymmetric supercavitating flow problems. An axisymmetric supercavitating potential flow passes an axisymmetric cavitator and immediately a cavity is formed behind the cavitator. Because of the smattering knowledge of the cavity closure region at the downstream of the cavity, a model called Riabouchinsky is applied to express the closure condition. According to this model, an image body is introduced at a certain distance downstream of the real body to make the cavity closed. A software pack, based on a CFD code, is developed to solve the axisymmetric supercavitating flows behind all types of axisymmetric cavitators (such as disk, cone, sphere, etc). An initial guess is made for the cavity boundary. Then an iterative procedure, which is converged by satisfying a norm, is developed within the CFD code to adjust the free boundary location of the cavity. The objective of this study is to find the shape and size of the cavity, cavitation number and drag coefficient of the cavitator. The numerical results are presented for supercavitating flows around the disks. Comparison of present results with the analytical and experimental data shows the superior accuracy of the boundary element method.

کلیدواژه ها:

Boundary Element Method ، Supercavitating Flows ، Cavitator ، Cavity Closure ، Drag Coefficient ، Cavitation Number