Verification of a Modular Hybrid DSMC-CFD Simulation Method Implementation for Expanding Rarefied Flows

We present a computational study of rapid gas flow expansion through a conical noz zle into a cryogenic chamber conducted using the hybrid CFD-DSMC method, known as Modular Particle Continuum (MPC) method, as it has been implemented within the US3D software suite. Our primary objective is to verify that our implementation of the MPC method is robust and accurate. Guided from work by other authors we established the pa rameters for the hybrid method to simulate this flowfield. We started with a CFD result, segmented the domain to have one-way coupling to the DSMC method, and performed a number of simulations to tune the hybrid method. Our results show mixed success in predicting particle mass-flux, accurately predicting the flow of the expanding plume, and under-predicting mass-flux in the lateral field of the domain.