Effect of wall inclination on the mean flow and turbulence characteristics in a two-dimensional wall jet

Abstract

Mean velocity and turbulence measurements, using hot-wire anemometry, were made up to 20 nozzle widths downstream of a nozzle in a two-dimensional (2-D) wall jet facility in which the angle of inclination of the wall to the nozzle was varied from 0 to 90° for a nozzle exit Reynolds number of 10,000. The effect of the wall angle (β) on the spatial development of the velocity field of the jet has been documented for β = 0°, 15°, 30°, 45°, and 90°. Results indicate that in the range 0° ⩽ β 5 45°, as the wall angle β increases, the centreline velocity decays faster, and the jet spreads faster, resulting in a shorter potential core and increase in jet volume entrainment. The positions of reattachment of the jet to the wall for various β have been deduced from surface pressure measurements and flow visualisation techniques.