Influence of curvature on turbulent flows downstream a backward-facing step

Curved and straight test sections were used to study turbulent flow development downstream a backward-facing step. The measurements were obtained in turbulent air flow for a Reynolds number Re-h,Re- based on step height of 6600. The mean velocities and six components of Reynolds stresses were measured downstream the reattachment region using hot-wire anemometers. The now integral parameters on both the bottom and top wails, in the downstream direction, were estimated. The distributions of wall pressure along the two test sections were determined. The reattachment length was measured using thermal tuft and visualization technique. In the curved test section there exists a secondary now which is directed toward the center of curvature. The measurements demonstrate an increase in the resistance to the flow caused by curvature of the channel. It is also demonstrated that the length of the reattachment region decreases as the secondary flow moves from the pressure side to the suction side of the curved channel.