Effects of Surface Roughness on Turbulent Transonic Flow Over Circular Arc Bumps in a Channel

Abstract

AbstractTurbulent transonic flow over circular arc bumps in a channel is computed to determine the effects of surface roughness on shock/boundary layer interaction. Initially the performance of several turbulence models for the computation of transonic flow over bumps is evaluated against the results of two different experiments. The k-ω model on the whole showed reasonable performance considering the optimal compromise between accuracy and CPU time requirement, which is subsequently employed for the surface roughness study for the confined channel flow over a bump. Computations are done for various equivalent sand grain surface roughness heights of the bump surface. The influence of the increase in surface roughness height transcends over onto the shock boundary layer zone and the observations are discussed. Upstream movement of the shock and increase in the skin friction coefficient with increasing surface roughness are observed.