Oblique shock

About: Oblique shock is a research topic. Over the lifetime, 6551 publications have been published within this topic receiving 119823 citations.

Pressure Recovery for Missiles with Reaction Propulsion at High Supersonic Speeds (The Efficiency of Shock Diffusers)

Abstract: The problem of the intake of air is treated for a missile flying at supersonic speeds and of changing the kinetic energy of the air into pressure with the least possible losses. Calculations are carried out concerning the results which can be attained. After a discussion of several preliminary experiments, the practical solution of the problem at hand is indicated by model experiments. The results proved very satisfactory in view of the results which had been attained previously and the values which were anticipated theoretically.

Turbulent Boundary-Layer Properties Downstream of the Shock-Wave / Boundary-Layer Interaction

Abstract: An experimental investigation was conducted to study the interaction between a shock wave and a turbulent boundary layer. Compression corner models mounted on a wind tunnel floor were used to generate the oblique shock wave in the Mach 2.94 flowfield. Ramp angles of 8, 12, 16, 20, and 24 deg were used to produce the full range of possible flowfields, including flow with no separation, flow with incipient separation, and flow with a significant amount of separation. The principal measurement technique used was laser Doppler velocimetry (LDV), which was used to make two-component coincident velocity measurements within the redeveloping boundary layer downstream of the interaction. The results of the LDV measurements indicated that the boundary layer was significantly altered by the interaction. The mean streamwise velocity profiles downstream of the separated compression corners were very wake-like in nature, and the boundary-layer profiles downstream of all the interactions showed an acceleration of the flow nearest the wall as the boundary layers began to return to equilibrium conditions. Significant increases in turbulence intensities and Reynolds stresses were caused by the interactions, and indications of the presence of large-scale turbulent structures were obtained in the redeveloping boundary layers.

Large-Eddy Simulation of Shock/Boundary-Layer Interaction

Abstract: This work considers numerical simulations of supersonic flows when shock/turbulent boundary layer interaction occurs. Such flows reveal the existence of complex mechanisms, which need to be carefully investigated for efficient design of propulsion systems. In this study, large-eddy simulation is used to investigate unsteady mechanisms. Since a shock-capturing scheme is used, a hybrid numerical scheme has been developed to reduce its dissipative properties. The issue of the generation of coherent turbulent inlet boundary conditions is also addressed. To avoid introducing artificial low-frequency modes that could affect the interaction, a method based on a digital-filter approach originally developed by Klein et al. (2003) and modified by Xie & Castro (2008) and Touber & Sandham (2009) is used to provide a synthetic-inflow condition over a relatively short distance. The obtained results are analyzed and discussed in terms of mean and turbulent quantities. Excellent agreement between LES and experimental data is obtained for both the undisturbed boundary layer and the shock impingement region. In the latter case, oscillations of the reflected shock occurring at low frequencies are observed, in agreement with previous numerical and experimental findings. Moreover, simulations reveal the presence of such frequencies mainly near the shock foot and within the recirculation bubble. This point gives credit to the hypothesis that the instabilities of the reflected shock are due to the intrinsic low-frequency movement of the shock/bubble acting dynamically as a coupled system.