Patent Document ID: 20170076026
Application ID: 14854309
Patent Flag: 0

Claim One:
1. A method of conducting a time-marching numerical simulation of an underwater explosion comprising: receiving, in a computer system having an Arbitrary Lagrangian-Eulerian (ALE) based finite element analysis (FEA) application module installed thereon, characteristics of an underwater blast source and a FEA model having a plurality of nodes connected by a plurality of finite elements representing a fluid domain surrounding the blast source; identifying, by the ALE based FEA application module, those nodes and finite elements located on the fluid domain's original outer boundary as original border nodes and original border elements, respectively; creating, by the ALE based FEA application module, one layer of new border nodes to form one layer of new border elements outside of the fluid domain's original outer boundary between the original border nodes and the new border nodes, the new border elements being so sized that none of the new border elements is smaller than smallest one of the original border elements; associating, by the ALE based FEA application module, each of the new border elements with a closest neighboring original border element as corresponding master element, and each of the new border nodes with a closet original border node as corresponding master node; obtaining, by the ALE based FEA application module, simulated fluid behaviors as a result of an underwater explosion originated from the blast source by conducting a time-marching numerical simulation using the modified FEA model for a predetermined duration in a plurality of time steps; at each time step, performing, by the ALE based FEA application module, operations for avoiding blast wave reflections from the fluid domain's original outer boundary as follows: (a) computing said simulated fluid behaviors of all of the finite elements except the new border elements, said simulated fluid behaviors including at least element strains, element stresses, and nodal velocities; (b) saving said simulated fluid behaviors of the original border elements and the original border nodes into respective lookup tables with each lookup table per said each of the original border elements, said each lookup table being configured to store said simulated fluid behaviors for a predefined number of time steps in a first-in-first-out manner; (c) calculating a blast wave propagation time for said each of the new border elements from the corresponding master element; (d) determining said simulated fluid behaviors of said each of new border elements by interpolating, with the calculated blast wave propagation time, the previously-stored simulated fluid behaviors in the corresponding master element's lookup table.