Investigation on the Characteristics of Water Flow over a Backward Facing Step under High Reynolds Number with Particle Image Velocimetry

The detailed experimental investigation on the 2D steady flow over a backward facing step in 30 Reynolds numbers range of 500 < Re < 50000 is carried out using particle image velocimetry (PIV) and the separation and reattachment flow region over a backward facing step is displayed on a particle image. The characteristic of time-averaged flow field structure, the velocity distribution on the different sections along flow direction and vertical direction, and the change law of the length of separation and reattachment region and the location of vortex center are obtained from low Reynolds number (Re=506) to high Reynolds number (Re=47901).