Author(s): Anurag Sharma; Suchismita Sahoo; Mahesh Patel

Linked Author(s): Anurag Sharma, Mahesh Patel

Keywords: Lluvial; Turbulence; Seepage

Abstract: The hydrodynamics of an alluvial channel was investigated in a tilting flume, considering the important effect of upward seepage. Seepage is an important explicit parameter of a sand bed channel that occurs in the form of lateral flow. The interface between the main flow and seepage flow is important to understand the transport of sediment and maintain a healthy river ecosystem. Therefore, the experiments were conducted for both no seepage and upward seepage runs to examine the effects of upward seepage on the on the hydrodynamics of an alluvial channel. Acoustic Doppler velocimeter (ADV) was used to measure the three-dimensional instantaneous flow velocities at a certain depth, which provide important results linked to the flow turbulence. The turbulent flow characteristics such as time-averaged velocity, Reynolds shear stresses, and turbulence intensity were analyzed for the case of no seepage and seepage flow. Results show that the level of turbulence decreased with the upward seepage, indicating lower sediment transport. The turbulent length scale also decreased with the upward seepage, which led to a decrease in the energy and momentum transfer induced by the larger eddy size in the near-bed region, and eventually, a lower rate of sediment transport with upward seepage. The results of the present study are useful for civil or hydraulic engineers since the knowledge of flow characteristics with seepage will improve the management of sediment in the natural river.

DOI: https://doi.org/10.3850/IAHR-39WC252171192022552

Year: 2022