The effect of shock-wave / boundary-layer interaction on turbulent spot propagation

We performed highly resolved large-eddy simulations (LES) of transitional shock-wave/boundary-layer interactions (SW/ BLI) in which a turbulent spot passes through a laminar shock-induced separation bubble. The initial condition consists of a laminar boundary-layer solution over a flat plate with a superimposed oblique shock which induces a separation bubble on the plate. An upstream-positioned initial disturbance triggers the turbulent spot that develops and encounters the SW/BLI region. Unlike the laminar boundary layer it does not separate but tunnels the SW/BLI region. Compared to a simulation without the SW/BLI region the spot growth is increased significantly during the passage. This finding supports the results of previous direct numerical simulations (DNS) in the literature. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)