DOI: 10.1615/ICHMT.2015.THMT-15
ISBN Print: 978-1-56700-427-4
ISBN CD: 978-1-56700-428-8
A plane turbulent wall jet on a fully rough surface
RESUMO
The mean velocity field and skin friction characteristics of a plane turbulent wall jet on a smooth and fully rough surface were studied using Particle Image Velocimetry (PIV). The Reynolds number based on the slot height and the exit velocity of the jet was Reo ~ 13,400. Comparison between the flows on the smooth and fully rough surfaces indicates the effect of surface roughness on the streamwise development of the wall jet and the skin friction coefficient is significant. For the fully rough regime, the effects of surface roughness were observed to penetrate into the outer layer and slightly enhance the spread rate for the outer half-width. On the other hand, roughness resulted in a decrease in the spread rate for the inner half-width compared to a smooth surface case, although the inner half-width itself was significantly larger on the rough surface.