Author(s): Vaclav Matousek; Jan Krupicka
Linked Author(s): Vaclav Matousek
Keywords: Intense transport; Hyperconcentrated flow; Bed load; Enclosed pipe; Experiment
Abstract: In the upper plane bed (UPB) regime, bed friction and sediment transport are interrelated. High bed shear agitates sediment transport and transported sediment can significantly increase bed friction. The log-law for bed friction employs a roughness parameter a size of which is related to the characteristic size of a bed grain. This approach is fine for weak transport of sediment but fails when the transport becomes intense. For intense transport, the bed roughness parameter should be related to the Shields parameter and this may cause troubles in flow computations. A simple method is suggested for predicting the bed friction coefficient using the same parameters for both weak- and intense transport of sediment in the UPB-regime. New experimental material collected in an enclosed rectangular pipe supports considerations used in developing the proposed method.
Year: 2013