Laboratory Investigation of Turbulent Flow Structure around a Bed-Mounted Cube at Multiple Flow Stages

Abstract

This research compares the spatially distributed turbulent wake characteristics associated with a submerged bed-mounted cube at three flow stages. The experiments were conducted in a large laboratory flat-bed flume at high Reynolds numbers. The velocity gradient under each flow condition was kept near constant, which yielded novel data that isolated the effect of flow depth on turbulent flow structure in the wake. Spatially distributed instantaneous three-dimensional velocities were recorded using multiple acoustic Doppler velocimeters (ADVs). With decreasing relative depth, marked variations in the spatial distributions of mean and turbulence statistics were observed that have important implications for local sediment mobility and fish habitat.