An Overset Method for High-Speed Particle/Flowfield Interaction Modeling

During supersonic and hypersonic flight, atmospheric particulates can impinge on the vehicle bow shock, cross the shock layer, and impinge on the boundary layer. Impinging particulates excite instabilities in the flowfield which can induce transition to turbulence. While existing methods have been largely successful in identifying key physics during the particle impingement process, they make simplifying and/or idealizing assumptions regarding the fluid around the particle, which results in under-resolution of key flow features during the impingement process. We propose an overset method to study particle impingement problems on high-resolution, arbitrarily-partitioned unstructured grids. We develop an accurate, characteristic-consistent, stable method to transfer the solution between background and overset grids. We develop a means for moving overset grids through a background grid, including use of a cell-unblanking scheme and a parallel collision detection algorithm. We validate our methods using canonical test cases. We apply the method to a particle impinging on a wedge at Mach 4. We extend the method to larger length scales using a supersonic store separation case.