Numerical Properties of the Discrete Gas Cavity Model for Transients

Wylie's discrete gas cavity model offers a simple way to simulate transients in liquids with a small amount of free gas, and to model vaporous and gaseous cavitations. It uses a constant and gas-free wave speed to avoid interpolations and a weighting factor to control numerical oscillations. The model has an intriguing ability to capture features associated with pressure-dependent wave speeds. We describe a von Neumann analysis on this model, shows why the need for the weighting factor and how to select it, and explains why the model exhibits variable wave speed features