抄録
Experimental investigation of relationship between flow resistance and a rough wall surface having regular two-dimensional semi-circular ribs was performed. A concentric cylinder device was used to carry out the experiments. This device allows to measure the flow resistance of the inner cylinder directly using a torque meter and the velocity distribution around the ribs by LDV. In the case of Taylor Couette flow, the logarithmic velocity distribution of the hydraulically smooth surface deviate from classical log-law and ? and ? change depend on Reynolds number. The downward shift from mean velocity distribution for smooth wall to that of rough wall, called roughness function (?U1^+) was examined. It was found that the roughness function was independent on the Reynolds number. Finally, ?U1^+ was correlated by frictional coefficient regardless to smooth or rough wall. The correlation formula is usable to another case having different rib geometry and size.
