A High Order Cut Cell Method for Numerical Simulation of Three Dimensional Hypersonic Boundary-Layer Transition with Finite Surface Roughness

Hypersonic boundary-layer transition can be affected significantly by surface roughness. Many important mechanisms which involve transition induced by arbitrary roughness are not well understood. Direct numerical simulation is broadly applied for investigating the roughness induced instability and transition in recent decade. But due to the complex computational geometry with embedded 3-D roughness, the use of body fitted curvilinear grids could prove to be very difficult. In our previous papers [44,45], we proposed a new high-order cut cell method to overcome the natural complexities in grid generation around curvilinear surface. The new algorithms of up to 4 ( ) O h accuracy have been derived and applied to simulate two-dimensional boundary-layer transition with finite surface roughness. Compared with two-dimensional roughness, the flow with three-dimensional isolated and distributed roughness is more complicated in analyzing and simulating. In this paper, we extend our previous new high order cut cell method to simulate three-dimensional hypersonic flow with finite surface roughness. The flow structure in three-dimensional boundary layer is investigated by using the new numerical approach.