Adapting a Scientific CFD Code to Industrial Applications on Hybrid Supercomputers

Abstract

The NOISEtte heterogeneous parallel code for simulating turbulent flow and aerodynamic noise is considered. In our previous works, high acceleration and parallel efficiency in scientific scale-resolving simulations using GPUs were reported. For parallelization, the MPI, OpenMP and OpenCL standards are used, the latter allows using GPUs from different vendors. However, the further transition to industrial-oriented applications brought more trouble. Instead of discussing the parallel algorithm, this work will focus on the problems that are not so obvious at first glance, which arise when developing a heterogeneous simulation code. How to deal with numerous simulation algorithm components, all those bells and whistles like wall functions, mixing plane and sliding interfaces, synthetic turbulence generators, a variety of boundary conditions, etc., that either need to be ported to the GPU side or incorporated directly from the CPU side? How to maintain and modify the OpenCL code in a growing number of source files? How to arrange the modularity of a complex heterogeneous software package? How to preserve reliability and fault tolerance, especially in the case of numerical schemes of increased accuracy, but reduced social responsibility? These issues are discussed here and some solutions will be proposed.