Turbulence characteristics in a rough open channel under unsteady flow conditions

Abstract

The present study investigates the vertical and lateral fluctuating velocity profiles under unsteady flow condition in a rectangular open channel. Experiment investigations are led with vegetated open channel flow. One hydrogram is passed through the rectangular flume with a fixed bottom with rough bed. An experiment is accordingly conducted to investigate the turbulence characteristics under unsteady flow conditions in a rough open channel for two different flow depths. For two typical flow depths, the velocities in both the rising limb and falling limb are observed. Hysteresis effect between stage-discharge (h ~ Q) rating curve between rising and falling limbs is illustrated. Turbulence characteristics, i.e. variations of Reynolds stress along the vertical and lateral direction are analyzed.