Towards a Fully Consistent DSMC-CFD Hybrid Method for Hypersonic Nonequilibrium Reacting Flows

We present the architecture and design considerations of a software framework that implements a hybrid continuum and particle method for hypersonic flow simulations in the nonequilibrium regime. The present methodology implements the hybrid computational fluid dynamics (CFD) and direct simulation Monte Carlo (DSMC) method of Schwartzentruber \& Boyd (Refs.~1-2), originally named the Modular Particle-Continuum (MPC) method. We added a number of augmentations to the original proof-of-concept implementation such that it can be deployed at industrial scale. The present framework is built over the existing CFD software suite that is US3D (Refs. 3-4) as an independent software plug-in, and uses the validated particle collision physics that are part of the MGDS flow solver (Refs. 5-7). The software framework is under development, with most of the primitives needed to build an automated implementation already in place. We describe how these constructs are to be combined in a software system for simulating certain classes of hypersonic flows. We describe the data structures that enable the DSMC method to be deployed efficiently on unstructured, body-fitted grids, and present a new algorithm for minimizing latency of the distributed/threaded parallelization of the method. Initial results are presented.