Separated flow and boundary layer research

The two dimensional corner study provides a unique framework bridging attached to separated flows. It only needs the measurements of local heat transfer and flowfield fluctuating measurements to be a complete description of an important shock wave boundary layer configuration. The study of a two dimensional reattaching free shear layer has provided a unique series of measurements, including the first turbulence data, at one flow condition and geometry. Reynolds number and geometry effects have yet to be studied, but the physics of reattachment have been explored in a way not heretofore examined. The investigation of three dimensional shock wave turbulent boundary layer interactions, specifically of the swept wedge, provides new insights into these complex flows with strong lateral gradients. The studies have revealed many new elements, but 'separation' and 'reattachment' take on new meanings which have yet to be clarified. Hypersonic turbulent boundary layers have been found to have very complex structures with very wide density variations and orders of magnitude unit Reynolds number changes across the layers. Highly viscous, laminar sublayers, are bounded by turbulent layers in which fluctuations of 50% are experienced. Many of the results of the present studies were used to test, validate, and guide major efforts in computational fluid dynamics. To date, the computations adequately describe attached flows, but do not capture the details of separated flows, although general characteristics of the flow field are predicted. The results of computations, sensitivity analysis, and testing of various models (turbulence) were important guides for the experimental studies.