On low-frequency unsteadiness in swept shock wave–boundary layer interactions

We derive a scaling law for the characteristic frequencies of wall pressure fluctuations in swept shock wave/turbulent boundary layer interactions presence cylindrical symmetry, based on analysis direct numerical simulations database. Direct large domains show evidence spanwise rippling separation line, with typical wavelength proportional to bubble size. Pressure disturbances around line are shown be convected at phase speed cross-flow velocity. This information is leveraged simple model low-frequency unsteadiness, which extends previous two-dimensional models (Piponniau et al. , J. Fluid Mech. vol. 629, 2009, pp. 87–108), and correctly predicts growth frequency sweep angle. Inferences regarding more general also discussed.