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The streamwise breathing motion of the separation bubble, triggered by the shock wave/boundary layer interaction (SBLI) at large Mach number, is known to yield wall pressure and aerodynamic load fluctuations. Following the experiments by Wang et al. (2012), we aim to evaluate and understand how the introduction of microramp vortex generators (mVGs) upstream the interaction may reduce the amplitude of these fluctuations. We first perform a reference large-eddy simulation (LES) of the canonical situation when the interaction occurs between the turbulent boundary layer (TBL) over a flat plate at Mach number = M 2.7 and Reynolds number = Re 3600 θ and an incident oblique shock wave produced on an opposite wall. A high-resolution simulation is then performed including a rake of microramps protruding by 0.47δ in the TBL. The long time integration of the simulations allows to capture 52 and 32 low-frequency oscillations for the natural case and controlled SBLI, respectively. In the natural case, we retrieve the pressure fluctuations associated with the reflected shock foot motions at low-frequency characterized by = − St 0.02 0.06 L. The controlled case reveals a complex interaction between the otherwise two-dimensional separation bubble and the array of hairpin vortices shed at a much higher frequency = St 2.4 L by the mVGs rake. The effect on the map of averaged wall shear stress and on the pressure load fluctuations in the interaction zone is described, with a 20% and 9% reduction of the mean separated area and pressure load fluctuations, respectively. Furthermore, the controlled SBLI exhibits a new oscillating motion of the reflected shock foot, varying in the spanwise direction with a characteristic low-frequency of = St 0.1 L in the wake of the mVGs and = St 0.05 L in between. According to the PIV measurements carried out by Piponniau et al. (2009), the recirculating region would be drained at low frequencies in response to the KH instability of the shear layer developing along the separation line. On the other hand, Ganapathisubramani et al. (2009) report that unsteadiness is linked to

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A statistical characterization of the turbulent flow produced in a vertical shock tube dedicated to the study of the Richtmyer–Meshkov instability (RMI) is carried out using laser Doppler velocimetry (LDV), time-resolved Schlieren images, and pressure histories. The time evolution of the phase-averaged velocity field and the fluctuating velocity levels produced behind the shock wave (SW) are first investigated for different configurations of a pure air homogeneous medium. This allows us to determine the background turbulence of the experimental apparatus. Second, the RMI-induced turbulent air/sulfur hexafluoride (SF6) mixing zone (TMZ) is studied both in its early stage of development and after its interaction with a reflected shock wave (RSW) (reshock phenomenon). Here, the gaseous interface is initially produced by a thin nitrocellulosic membrane trapped between two grids. One of the most consistent issues regarding such a process is the generation of a large number of fragments when the incident SW crosses the interface. These fragments are likely to corrupt the optical measurements and to interact with the flow. This work seeks to clarify the influence of these fragments on the statistical determination of the velocity field. In particular, it is shown that statistical convergence cannot be achieved when the fragments are crossing the LDV measurement volume, even if a significant number of identical experiments are superimposed. Some specific locations for the LDV measurements are, however, identified to be more favorable than others in the air/SF6 mixing configuration. This finally allows us to quantify the surplus of turbulence induced by the reshock phenomenon.