Numerical and experimental investigation of shock/turbulence interaction by hotwire technique

Abstract

In the present paper, an experimental investigation has been carried out to observe the amplification of turbulence intensity after shock/turbulence interaction by hot-wire technique. The hot wires are installed in the wake of the turbulent grids to measure the turbulence fluctuations before and after the reflected shock wave interaction with the turbulent field. Due to different grid plates, different strengths of turbulent fields are found behind the transmitted shock wave. It is observed that the turbulence fluctuations for less open area of the grid plate are higher than the turbulence fluctuations for more open area of the grid plate. Numerical simulations are also conducted on the experimental results where grid plate of 49.5 % open area is used. It is observed that the average longitudinal velocity line for the experimental velocity data simulate with numerical results properly and in some places, 5–7 % deviations are observed with numerical results. All the simulation results indicate that the present code with turbulence model is working properly for its initial conditions. The wall pressure fluctuations are also measured experimentally and substantial amplification of pressure fluctuations is occurred after the shock/turbulence interaction. The rate of dissipation of turbulent kinetic energy (TKE) and the levels of length scales are determined numerically by using k-8 turbulence model and it is observed that the rate of dissipation of TKE and the levels of length scales decrease after shock/turbulence interaction.