Numerical simulation of shock/cavitation-structure interaction

Abstract

An interesting real-life problem is the effects of underwater explosions on submerged/partly submerged structures such as surface ships or submarines. When such explosions are a distance away from the structure, shock waves and cavitation regions are formed which interact with each other as well as with the structure, hence making the process complicated to simulate. Here, we do not seek to simulate this entire process but aim to start with the basics of modelling an elastic structure coupled with a compressible fluid. In such problems, a novel finite-difference approach of modelling the elastic solid using the Naviers equation in Lagrangian form is adopted. The Euler equations with an appropriate EOS in Eulerian form are used to model the compressible fluid. The interface characteristics are developed using the modified Ghost Fluid Method and the position of the interface is determined by the Level-set method. Validation of this approach is accomplished by comparing the simulated solutions of some one-dimensional shock-tube problems with their respective analytical solutions.