Separated and Reattached Flows Effects of Pressure Gradient on Two-DimensionalSeparated and Reattached Turbulent Flows

An experimental program was designed to study the salient features of separated and reattached flows in pressure gradients generated in asymmetric diverging and converging channels. Reference measurements were also made in a parallel-wall channel to facilitate the interpretation of the pressure gradient flows. A transverse square rib located at the start of convergence/divergence was used to create separation inside the channels. In order to simplify the interpretation of the relatively complex separated and reattached flows in the asymmetric converging and diverging channels, measurements were made in the plain converging and diverging channel without the rib on the channel wall. All the measurements were obtained using a high resolution particle image velocimetry technique. From these measurements, mean velocity, Reynolds stresses and higher order turbulent quantities including terms in the transport equation of the turbulent kinetic energy were reported. The structure of flow was further investigated using a proper orthogonal technique.