A Three-Dimensional Sharp Interface Cartesian Grid Method for Solving High Speed Multi-Material Impact Problems

摘要

Large-scale computations are required to simulate physical phenomena involving detonation and shock waves in supernova formation, explosions and hypervelocity impact and penetration. The interaction of these waves with multi materials can result in complex wave structures in two and three dimensions. In addition, the embedded materials may experience large motions and deformation under the influence of the high-speed flows. In this paper, the main focus is on parallel implementation of a fixed Cartesian grid flow solver with moving boundaries. A higher order conservation scheme such as ENO is used for calculating the numerical fluxes and level sets are used to define the objects immersed in flow field. A Riemann solver based Ghost fluid method is used for interface treatment of embedded objects. The issues involved in parallelization of the moving boundary solver are presented with emphasis on strong shocks interacting with embedded interfaces (solid-solid) in three-dimensional compressible flow framework. The handling of moving boundaries, tracked using narrow-band levelsets leads to issues peculiar to the multi-processor environment; the solution to object passage between subdomains and treatment of ghost regions for inter-processor communication are also addressed. Example calculations for three-dimensional impact/penetration problems are presented.