Enabling First Principles Multiscale-Multiphysics Simulations of Complex Thermo-Fluid Systems Through Exascale Computing*

Understanding and controlling turbulence, aerothermodynamics, and propulsion processes in advanced thermo-fluid systems presents many challenges. A multitude of strongly coupled fluid dynamic, thermodynamic, transport, chemical, and heat transfer processes are intrinsically coupled and must be considered simultaneously in complex domains. These multiscale physics are not currently understood or modeled with sufficient accuracy. Without their inclusion, timely Research and Development of advanced systems will be significantly deficient. Exascale computing offers significant opportunities treat these physics with unprecedented accuracy and speed. However, the foundational hybrid-CPU+GPU architectures present many challenges to exploit their full potential power. This presentation will highlight the inherent challenges associated with porting complex multiphysics solvers to these architectures and the approach taken to achieve optimal performance using the RAPTOR code framework developed by Oefelein et al. as an example application.