Effects of turbulent boundary layer thickness on flow around a low-rise rectangular prism

The effects of upstream velocity profiles on the flow around a low-rise rectangular prism submerged in a turbulent boundary layer have been investigated. Three different boundary layer profiles are generated, which are characterized by boundary layer height, displacement thickness, and momentum thickness. Flow characteristics variations caused by the different layers such as those in turbulent kinetic energy distribution and locations of re-circulating cavities and reattachment points have been precisely measured by using a PIV (Particle Image Velocimetry) technique. Observations were made in a boundary layer wind tunnel at ReH = 7900, based on a model height of 40 mm and a free stream velocity of 3 m/s with 15 - 20% turbulence intensity.