Flow Relaxation Past a Transverse Square Rib in Pressure Gradients

Abstract

An experimental investigation is undertaken to study the salient features of separated and reattached flows over a transverse square rib in an asymmetric diverging and converging channel. To facilitate comparison, experiments were also performed in a parallel-walled channel for which the pressure gradient is nearly zero. The transverse square rib was located 1000 mm from the inlet of a given channel (at the inlet to the convergence/divergence section). A high-resolution particle image velocimetry was used to conduct the velocity measurements. From these measurements, isocontour plots of mean velocity, Reynolds shear stress, and spanwise vorticity in the vicinity of the rib were reported. The profiles of mean velocities, Reynolds stresses, triple products, and some of the terms in the transport equations for turbulent kinetic energy and Reynolds shear stress are reported in the separated and redevelopment regions as far downstream as 200 step heights.