Simulation of Unsteady Supercavitation Using Isentropic One-fluid Model

Abstract

The unsteady supercavitating flow is simulated to investigate its response to introduced perturbation. The flow is governed by a homogeneous cavitation model based on barotropic compressible Navier-Stokes equations. Compressibility effects of liquid are modeled by Tait equation of state (EOS), while inception and development of cavitation are described by isentropic one-fluid cavitation model. The governing equations are discretized on unstructured triangular mesh to deal with potentially complex geometry of underwater body. In this study, our interest is concentrated on supercavitating flow around a NACA0015 airfoil at different angles of attack and its time evolution when impacted by a pressure wave. The dimension and position of supercavity over airfoil are affected significantly by angle of attack. Under a weak pressure wave, supercavity boundary is deformed but it is able to recover to its original shape. This study indicates that performance of underwater device may be improved if the supercavitation over it is controlled carefully.