Experimental Studies Involving Flow Visualization Over Non-circular Geometries

Vortex dynamics plays a vital part in the transport of mass, momentum and energy of a flow field. Vortex manipulation is the way out for controlling any device that involves mixing of flow. In the present study, the size of recirculation zone behind the various non-circular geometries and various square blocks of different thicknesses 4, 6 and 8 mm is visualized. The physics behind the wake zone size manipulation for different Reynolds numbers is also investigated. Flow separation and reattachment points and distance of reverse flow for various geometries are observed and illustrated. Work is further extended for flow visualization over forward, backward and combined steps. Experimental analysis is done by using an open channel setup, which is fabricated to designed dimensions. Drag force and the coefficient of drag for various geometries with different set of inclinations (90° and 30 °) and at various Reynolds numbers are calculated. Plots are made between various Reynolds numbers and coefficient of drag, pressure uphill, reverse flow length and are analyzed with respect to different flow features.