Finite element analysis of shock-induced hull cavitation

Abstract

This paper describes the theoretical formulation and computational implementation of a method for treating hull cavitation in underwater‐shock problems. In addition, the method can be applied to the analysis of submerged structures that contain internal fluid volumes. In the present implementation, the doubly asymptotic approximation (DAA) serves to simulate a radiation boundary that is located away from the fluid‐structure surface at a distance sufficient to contain any cavitating region. The enclosed fluid is discretized with volume finite elements that are based upon a displacement‐potential formulation. An explicit time‐integration algorithm is used to advance the solution in the fluid‐volume region, implicit algorithms are used for the structure and DAA boundary, and a staggered solution procedure has been developed to treat the interface condition. Results for two example problems obtained with the present implementation show close agreement with those obtained by other methods.