EFFECT OF EXTERNAL TURBULENCE ON SEDIMENT PICKUP RATE

Abstract

Influence of turbulence on sediment pickup rate was investigated. Pickup rates with external turbulence generated by a grid structure were measured in a channel. It was found that the rates were much larger than those for non-turbulent conditions. A new formula in which external turbulence was taken into account for Shields parameter evaluation was proposed. In the formula, effect of inertia force by turbulence acting on sediment particles was included as well as the enlarged drag force caused by fluctuating velocity.