階段状河床波上の流れと抵抗則

Abstract

Shear stress distribution and friction law of flow over step-pool bed forms are basicallyimportant for treating the sediment transport in mountain streams. The present study discussesthe problems such as velocity and shear stress distributions as well as a friction law of flow overstep-pool bed forms.The equipment to measure the shear stress on bed surface is devised. Data of shear stressdistributions are obtained on an artificial step-pool bed form. The meanings of the data arediscussed in relation to those of velocity distributions.The friction law of flow over the step-pool bed form is developed by using such an ideathat energy consumption of a main flow past the crest of the bed form is balanced by the pro-duction of turbulence or eddy in the separation region. The equation of flow resistance is suc-cessfully compared with the flume data which are obtained from the experiments of flow overstep-pool bed, dune bed and strip-roughness bed.