Large-Eddy Simulation of a Near-Normal Shock/Turbulent-Boundary-Layer Interaction

Features of a normal shock/turbulent-boundary-layer interaction at Mach 1.54 are examined using large-eddy simulation. The geometry used consists of an internal passage divided into an upper unchoked section and a lower choked section by a shock-holding plate. This geometry and incoming Mach number produce a nearly normal shock and lambda-foot structure on the lower wall, leading to separation in the incoming, [Formula: see text], turbulent boundary layer. The shock structure is slightly detached from the leading edge of the shock-holding plate and exhibits unsteady but statistically stationary oscillations in the streamwise direction. Unsteady and time-averaged quantities are then examined upstream, inside, and downstream of the interaction region. The interaction of the front foot of the [Formula: see text]-shock with the turbulent boundary layer induces strong separation. The characteristic low-frequency oscillation in the main trunk of the shock is also present in the spectra of wall pressure fluctuations, turbulent kinetic energy, and instantaneous separation location. The shock-induced separation amplifies and redistributes the turbulent Reynolds stresses from the incident boundary layer to the separated shear layer.