An iterative scheme for axisymmetric supercavitating flow

Artikel i vetenskaplig tidskrift, 2009

This article presents a numerical investigation of axisymmetric supercavitating flow. It is assumed that such a flow field could be estimated by a potential flow that neglects the viscosity effects and rotational motion of the fluid and assumes the flow as an irrotational flow field. One of the most adequate methods for modelling potential fields is the boundary element method, which is employed in this article. A novel iterative scheme is used to capture the free surface of an axisymmetric supercavity. This numerical algorithm is based on updating an initial guess for the cavity's boundary; the convergence criterion is the pressure amount on the free surface of the cavity, which converges to a constant value. To obtain finite lengths for supercavities, a cavity closure model is applied. The results are in good agreement with similar analytical and numerical solutions as well as the existing experimental data for supercavities characteristic properties and the drag coefficient on cavitators. The present iterative numerical algorithm is reliable for predicting the characteristics of a supercavitating flow. Moreover, the feasibility of the cavity capturing in a flow field with low cavitation number is especially attractive.