Author(s): Anurag Sharma; Mahesh Patel; Bimlesh Kumar
Linked Author(s): Mahesh Patel
Keywords: Alluvial channel; Non-uniform sand; Sheet layer; Turbulence
Abstract: An experimental study has been done to observe changes in the turbulence characteristics of flow in the presence of a sheet layer in an alluvial channel composed of a non-uniform sediment mixture. The sheet flow layer is a thin layer having few centimeter thickness comprised of moving sediment particles and suggested that the bed remains plane under sheet flow conditions and becomes independent of other bed topography features. Instantaneous velocity measurements were taken at the centre line of sheet f low layer by the Acoustic Doppler Velocimeter (ADV). The present study addresses on the flow zone in the vicinity of the bed surface. The turbulent events, such as stream wise velocity, Reynolds shear stresses, and turbulence intensities were found to be increasing and vertical velocity was found decreasing with a sheet layer. The presence of a sheet layer also affects the turbulent energy production and energy dissipation which influenced higher turbulence production and a lower TKE dissipation rate.
Year: 2020