PIV Investigation of an Open Channel Flow Over a Forward Facing Step

The characteristics of an open channel turbulent flow over a forward facing step (FFS) are investigated in the present study. Two step heights, h = 6 and 9 mm, at Reynolds number, Re_h, (based on the approach freestream velocity, U₀, and step height, h) of 1900 and 2800 respectively were studied. Particle image velocimetry technique (PIV) was used to obtain detailed velocity measurements upstream of the FFS, in the reattachment region (x/h = 0, 1, 2) and in the redevelopment region (x/h = 4, 10, 15 and 50). The boundary layer integral parameters, mean velocity profiles and Reynolds stresses obtained in the reattachment and redevelopment region are used to document some of the salient features of the flow.