An Experimental Study of Shear Stress Distribution in a Compound Meandering Channel

Abstract

Naturally river flow can be characterized as compound meandering channel in which the shear stress characteristics are quite intricate. Reliable investigation of shear stress distribution in a compound meandering channel is essential in solving a variety of river hydraulics and engineering problems, designing stable channels and bank protection, understanding the mechanism of sediment transport. A laboratory experiment has been conducted in a compound meandering channel with symmetric cross-sections having floodplain width ratio of 1, 1.67, 2.33, 3 and depth ratio of 0.20, 0.30, 0.35, 0.40 using the large-scale open air facility in the Department of Water Resources Engineering, Bangladesh University of Engineering and Technology (BUET), Dhaka, Bangladesh. Point velocity data have been collected using an ADV (Acoustic Doppler Velocity Meter) for different depth and width ratio at different locations of a compound meandering channel. Shear stress is calculated from the Prandtl-Von Karman Universal Velocity Distribution Law. The laboratory experimental investigation reveals that shear stress increases with the increase of depth and width ratio and low magnitude of boundary shear is observed in the outer bend as compare to the inner bend in a compound meandering channel.