Density and pressure fluctuations have been investigated experimentally in turbulent flows of air and argon in a shock tube as well as the interaction of the reflected shock wave with turbulence. The shock wave reflected from the perforated end of the shock tube and interacted with the turbulent flow. The Mach number of the incident shock wave varied from 1.9 to 3.9. The Mach number of the reflected shock were equal to 1.4 – 2.4. We measured the length scale of the turbulent fluctuation behind the incident shock. It was found that the pressure behind the reflected shock in a turbulent flow is greater than the corresponding value in the laminar flow ceteris paribus. The overpressure is equal to 12% in argon and to 9% in air.
47.27.Cn Transition to turbulence
$^1$Faculty of Physics, M.V. Lomonosov Moscow State University.