Turbulent Structure of Water and Clay Suspensions with Bed Load

Abstract

The effect on turbulence of adding coarse sand, carried as bed load, in flows of water and clay suspensions was studied. The results showed that the mean velocity of the flows carrying bed load was smaller and the turbulence intensity was greater than those in the flows without bed load. The presence of bed load resulted in higher Reynolds stress and larger velocity gradient, and thus greatly enhanced the energy transmitted from the mean motion to turbulence. In flows of clay suspension, turbulence developed in the lower flow with quite high turbulence intensity, while laminar flow occurred in the upper flow. However, with bed load the entire flow became turbulent. The position of maximum turbulence intensity was more distant from the bed. The average turbulence intensity increased with rate of bed‐load transport. The spectrum of turbulent energy shifted to higher frequencies in bed‐load‐carrying flows.