Natural Cavitation in High Speed Water Entry Process

Abstract

Phase transition between liquid and vapor comes into existence when the velocity of the water entry device is sufficiently high, which will affect the flow field formation and development. Numerical simulations, implemented in the commercial CFD package FLUENT, with three popular cavitation models and some equation modifications by UDF, have been conducted to investigate the natural cavitation in high speed water entry process. Comparisons with experimental results were done to verify the applicability of each model. With the preferable model, the formation and development of natural cavitation is presented, with the pressures inside water entry cavity analyzed. Cases with three water entry velocity magnitudes were simulated specially to study its influence to natural cavitation and water entry process. The results show an order of the natural cavitation in high speed water entry process, and provide an effective method to simulate such problems. Keywords-high speed water entry; cavitation model; multiphase flow;natural cavity; pressure feature