Simulation techniques for spatially evolving instabilities in compressible flow over a flat plate
The spatially evolving boundary layer over a flat plate is studied in two dimensions by direct numerical simulation of compressible Navier-Stokes equations. The authors focus on two aspects: the spatial discretization method, and the treatment of artificial boundaries, primarily the outflow boundary. A second-order and a fourth-order accurate central schemes are compared for the spatial discretization. Nonreflecting boundary conditions are proposed for the outflow boundary, and an additional buffer domain in the vicinity of outflow boundary is introduced where the flow is gradually brought back to the laminar case by multiplying the disturbancies by a damping function. An explicit four-stage compact-storage Runge-Kutta scheme is used for time integration. The central difference approximations and the buffer domain treatment are extensively evaluated for a series of test cases and compared to solutions of simplified mathematical models, such as linear stability theory and linear parabolized stability equations.
explicit four-stage compact-storage Runge-Kutta scheme
scientific article; zbMATH DE number 1143702