Updated VOFIRE algorithm for fast fluid–structure transient dynamics with multi-component stiffened gas flows implementing anti-dissipation on unstructured grids

The present paper is dedicated to the simulation of fast transient phenomena involving multi-component flows with fluid–structure interaction and ALE grid motion, where the fluid interfaces are tracked using the VOFIRE anti-dissipative scheme for unstructured meshes. It introduces an extension of the existing scheme in EUROPLEXUS software, written for liquid–gas flows only, to handle a combination of stiffened gases as equations of state for the fluid components, thus increasing its genericity and overcoming some limitations, at the cost of significantly modifying its implementation. The proposed methodology is proven to achieve its goals through validation examples with fluid only, such as the sloshing of a liquid in a decelerated tank or a gas–gas interaction with Richtmyer–Meshkov instability. Two large scale three-dimensional examples with full fluid–structure interaction are then provided to fully demonstrate the capabilities and the robustness of the complete proposed computational framework.