High performance computing of stiff bubble collapse on CPU-GPU heterogeneous platform

Abstract

SCB is an efficient fluid solver developed for computing two-phase compressible flows involving strong shocks and expansion waves. It solves a four-equation diffuse-interface model, which is derived from the five-equation model proposed by Kapila et al. The governing equations are discretized by a finite volume method with explicit time stepping. SCB uses a fully parallel environment via Message Passing Interfaces (MPI). With the fast growing number of heterogeneous computing platforms including disparate hardware architectures, it becomes nowadays necessary to develop hybrid parallelization strategies with a special care to portability. In this context, we present an heterogeneous computing framework based on MPI library and OpenACC. The choice of OpenACC is discussed. Performances, scalability and adaptability are illustrated through a series of tests on an heterogeneous architecture. Validations are proposed on various bubble collapses, in free-field or near a rigid wall. Comparisons are done with existing results and analytical solutions. Furthermore a stiff shock-induced bubble collapse demonstrates the capabilities and the high potential of the code.