Numerical Modelling of Shock Wave and Pressure Pulse Generation by Underwater Explosions

摘要

The continuing development of multi-purpose finite element analysis (FEA) codes permits their application to provide new and penetrating insights into the difficult subject of underwater explosive effects and the coupled response of nearby structures. In this paper we investigate the use of one such code (DYNA2D) to model the physical processes associated with an underwater explosion. We compute models covering a range in explosive masses and depths of detonation. The models are shown to simulate much of the important physics of an underwater explosion including: explosive detonation, shock wave generation and transmission, bubble pulsation and the generation of bubble pulse pressure waves. The model results are compared to published experimental data for key features of an underwater explosion such as bubble periods, maximum bubble radii and characteristics of the shock and bubble pressure waves. The good quantitative agreement found for many of these features demonstrates that FEA codes can be used to model important aspects of an underwater explosion. Nevertheless a number of limitations are identified, the most serious of which is the absence of some important energy loss mechanisms associated with bubble collapse.