Three Dimensional Parallel Compressible Multi-material Flows Anil Kapahi * , John Mousel*,Shiv Kumar Sambasivan ** and H.S.UdayKumar § Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA – 52242 Shock Waves and Detonation waves have been topic of cutting edge research for decades. The interaction of these waves with multi materials can result in complex wave structures in two and three dimensions. Large-scale computations are required to simulate physical phenomena involving detonation and shock waves like supernova formation, explosions and hypervelocity impact and penetration. In this paper we describe the parallel implementation of 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. This paper describes the methodology for parallelization with emphasis on strong shocks interacting with embedded interfaces (solid-fluid, solid-solid and fluid- fluid) in three-dimensional compressible flow framework. It also explains the handling of moving boundaries in multi-processor environment and definition and treatment of ghost layer in three dimensions. I. INTRODUCTION The levels set[1] based sharp interface methods are very popular for fixed Cartesian grid problems. This treatment reduces the complexity involved in grid generation and helps in defining complicate shapes using level set functions. In our previous papers, a simple and a unified Cartesian grid approach were developed for accurate representation of embedded solid and fluid objects in high-speed compressible multiphase flows. The methodology formulated was based on the Ghost Fluid Method (GFM) due to Fedkiw and coworkers[2]. The pivotal theme in the GFM approach lies with the definition of band of ghost points corresponding to each phase of the interacting media. The ghost band when supplied with appropriate flow conditions, together with the respective real fluid, constitutes a single flow field. Hence higher order numerical schemes such as ENO[3] and WENO[4], developed for single component flows * Graduate Student, Department of Mechanical and Industrial Engineering, anil-kapahi@uiowa.edu * Graduate Student, Department of Mechanical and Industrial Engineering, john-mousel@uiowa.edu ** Post Doctorate, Los Alamos National Lab, shivkumar.sam@gmail.com § Professor, Department of Mechanical and Industrial Engineering, ush@engineering.uiowa.edu 49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition 4 - 7 January 2011, Orlando, Florida AIAA 2011-648 This material is declared a work of the U.S. Government and is not subject to copyright protection in the United States.