Investigation by Particle Image Velocimetry Measurements of Oblique Shock Reflection with Separation

The organization and length scales of turbulent structures and unsteadiness generated in a shock-wave-induced separation at Mach number of 2.3 are investigated experimentally using particle image velocimetry. Processing of the velocity fields displays and demonstrates the existence of structures in the mixing layer developed in the separation bubble. Moreover, we show in evidence a link between the reflected shock excursions and the size of the separated flow. This overview of the spatial organization of the interaction provides a more comprehensive picture of the flow. Nomenclature C f = friction coefficient L = length of the interaction M = Mach number Re = Reynolds number based on the momentum thickness S L = Strouhal number T t = stagnation temperature U 0 = upstream external velocity U ‡ = V=u u = friction velocity V = Van Driest transformed velocity X = x X 0 †=L X 0 = mean position of the reflected shock x = longitudinal coordinate Y = y= 0 y = normal to the wall coordinate y ‡ = yu = 0 = upstream boundary-layer thickness = incidence angle of the shock generator = kinematic viscosity