Advanced Fluid Modeling Capability for Underwater Shock Analysis of Naval Platforms

The practical ability to do realistic underwater shock simulations in three (and often even two) dimensions is beyond the reach of existing software and hardware. The thrust of the work proposed here is to utilize current advanced capabilities to attacksuch problems by innovatively combining a variety of proven techniques; this will lead to simulation efficiencies that are orders of magnitude better than are now available. In particular, we propose to merge two existing computer codes that have advancedfluid modeling features. One of the codes treats mixtures of materials by means of coupled level-set methods, volume-of-fluid techniques and dynamic adaptive mesh refinement. Designed primarily for incompressible fluid flow, it uses time integrationmethods classified as semi-implicit. The second code, which deals with the physics of underwater explosions and shock wave propagation in compressible materials, uses time integration methods classified as mixed explicit-explicit. The combination of thesetechniques will provide an accurate yet efficient computer program for simulating underwater shock problems.This work will be of primary interest to the U.S. Navy and their contractorsbecause it will improve the accuracy and efficiency of the analysis procedures used to evaluate and adjust the designs of ships as well as their internal components. As a result, lives may well be saved, and reduced production and operating costs may beexpected. The software would be useful to commercial shipbuilders in any serious effort to reduce ship exposure to terrorist bombings.