THE TURBULENT FLOW STRUCTURE IN STEPPED STEEP OPEN-CHANNEL

Abstract

Stepped steep open-channels have watched with interests such as landscape effect and water quality purification function by aeration besides the energy dissipator. The authors have made some experiments to clarify the flow structure and considered mean flow characteristics by measuring flow depth fluctuations, mean flow velocity and pressure head on one step. In this study, we conducted an experimental examination on the turbulent flow characteristics obtained with hot-film anemometer to elucidate accelerating flow over one step. Experimental results showed that Reynolds normal stress and shear stress clearly decreased with downstream distance from step edge by the effects of favorable pressure gradient, and inverse cascade of energy happened.