We study how the presence of a sweep angle affects the behavior of a shock-boundary layer interaction. The study is carried out using spanwise-periodic Large-eddy Simulations with a freestream Mach number of $M=2.7$ and a Reynolds number based on the momentum thickness of ${\mathrm{Re}}_{\theta }\simeq 3200$. Several sweep angle values are investigated, namely, $\beta =0^{\circ }, {15}^{\circ },{20}^{\circ }$, and ${40}^{\circ }$. The mean flow is first analyzed, showing an enlargement of the separation area, both in longitudinal and wall-normal directions when the sweep angle is increased. Strong flow deviation is also recovered downstream of the reattachment point for swept cases. With regard to the unsteady dynamics of the interaction, energy is found near the mean separation location for intermediate frequencies (corresponding to a Strouhal number ${\mathrm{St}}_{L_{\mathrm{sep}}}\approx 0.15$ for $\beta ={15}^{\circ }$ and ${20}^{\circ }$ and ${\mathrm{St}}_{L_{\mathrm{sep}}}\approx 0.23$ for $\beta ={40}^{\circ }$ in the wide domain). The latter are significantly higher than the very low frequencies ($0.01<{\mathrm{St}}_{L_{\mathrm{sep}}}<0.1$) usually associated with the unswept interaction. We relate these intermediate frequencies to spanwise-traveling structures, using the Proper Orthogonal Decomposition of velocity fluctuations in a volume located around the interaction region. The influence of the spanwise extent of the computational domain is also examined. This leads to the conclusion that a sufficiently wide computational domain is necessary to allow for the development of these structures and the appearance of the aforementioned intermediate frequencies.

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• Boundary layers
• Compressible boundary layers
• Compressible turbulence
• High-speed flow
• Shock waves