Simulation of Cylinder Implosion Initiated by Underwater Explosion

摘要

The traditional study of underwater explosions (UNDEX) with respect to ship damage became of interest during World War II when torpedo explosions near a ship created more damage than a direct hit. Following the war, many full scale ship shock trials were conducted that provided much of the empirical data that is used in the field today. However, one type of shock phenomena became of interest in the late 1960s that potentially could be more damaging than a typical underwater explosion; an implosion. Crude implosion experiments were conducted in the late 1960s. Although these experiments collected data on pressure waves, more emphasis was placed on the acoustical properties associated with an implosion event. Today, one of the Navy's concerns is about the potential for the implosion of a pressure vessel in close proximity to a submarine hull. A computational approach is desired that will predict the source strength of an implosion. This thesis will cover the basic principals of underwater shock phenomena, including explosions and implosions. Drawing from previous experiments and computational simulations, a detailed investigation of the implosion event will be made using, DYSMAS, a coupled Eulerian-Lagrangian solver. DYSMAS will be used to compare the characteristics of implosion and explosion events.