An open-source hybrid CFD-DSMC solver for high speed flows

During re-entry, a spacecraft will experience flow conditions ranging from highly rarefied to continuum. To simulate regions in between, a hydrodynamic-molecular gas hybrid solver should be used to provide accuracy and effciency. Currently available hybrid codes are in-house codes or do not provide the capabilities to simulate all of the phenomena a spacecraft will experience during re-entry. An open-source CFD-DSMC hybrid code is being developed within the OpenFOAM framework, coupling the solvers dsmcFoam and hy2Foam. In this paper, comparison between the CFD, DSMC and hybrid codes have been performed for simple cases. The dsmcFoam and the hybrid code have shown to compare satisfactorily.