Second Symposium on Turbulence and Shear Flow Phenomena
DOI: 10.1615/TSFP2
QUADRANT ANALYSIS OF ROUGH AND SMOOTH SURFACE CHANNEL FLOWS
pages 335-340
DOI: 10.1615/TSFP2.560
ABSTRAKT
A comparison between the turbulent flows in a smooth and rough wall channel are reported. It is demonstrated that even though the outer layer may appear to be unaffected by the surface condition, since the mean velocity defect profiles are identical, significant modifications to the turbulent stresses as far out as y/h~ 0.4 are found. Inside this limit the contributions from the fourth quadrant are found to be much more dominant in the rough case than over the smooth wall, confirming earlier findings that surface roughness tends to stimulate sweep type of motions.