Abstract
Experimental analysis for determining the general relationship between surface roughness and flow resistance has been performed. In this study, we measured the actual flow resistance on the rough wall with regularly distributed rectangular ribs by using the concentric cylinder device and velocity distribution was also measured by LDV. Based on the present result, we proposed a simple equation for predicting flow resistance over rough wall. For making the equation, we evaluated the factional drag and pressure drag acting on the surface of ribs separately by the measured velocity distribution. Consequently, we can also estimate total flow resistance. Compared the estimated flow resistance by measured velocity distribution with the actual flow resistance measured by toque of the inner cylinder, these results had good agreement and validity of a simple prediction equation was confirmed.
