PIV Study of Three-Dimensional Wall Jet Over Smooth and Rough Surfaces

This paper reports experimental study of three-dimensional turbulent wall jet over smooth and rough surfaces. The wall jet was created using a square nozzle of size 6 mm and flow into an open channel. The experiments were performed at a Reynolds number based on the nozzle size and jet exit velocity of 4800. A particle image velocimetry was used to conduct detailed measurements over the smooth and rough surfaces at various streamwise-transverse and streamwise-spanwise planes. From these measurements, mean velocities and turbulent quantities were extracted at selected locations. The distributions of the mean velocities, turbulent intensities and Reynolds shear stress were used to provide insight into the characteristics of three-dimensional wall jet flows over smooth and rough surface.