Author(s): Ijaz M. Khan; Richard R. Simons; Anthony J. Grass
Keywords: Diffusion; turbulence; wall roughness; pollution; street canyon
Abstract: In this paper, the vertical diffusion was measured from line source injector under neutral boundary condition over rib-roughened wall in a water channel. The variation in gap distance between the rib-roughened wall characterized skimming flow (ribs closely spaced), wake interference flow and isolated roughness flow (ribs widely spaced). The effect of change in local bed geometry was noticed with the increase in turbulence energy production, which was correlated with the vertical diffusion.