Author(s): Nian-Sheng Cheng
Linked Author(s): Nian-Sheng Cheng
Keywords: Friction factor, large-scale roughness, Manning-Strickler formula, rough pipe, gravel bed
Abstract: The Manning-Strickler (MS) formula is only applicable for small-scale roughness conditions. This study demonstrates that with simple modifications, it can be also applied for large-scale roughness to estimate the friction factor for pipe and open channel flows. The modifications are developed simply by considering the roughness induced flow constriction. Without adjusting constants involved, the derived formulas agree well with experimental data in the range of small to large-scale roughness. Comparisons are presented with large-scale roughness data, which include three series of rough-pipe data, of which two are collected in this study and the other is reported in the literature, and 404 sets of gravel-bed data from five previous studies
Year: 2017