Boundary Shear Distribution in Meandering Channel

Abstract

For many years, river modelling has been a core subject in the field of hydraulics. Over the past few decades, various attempts have been made to build models for flow. The distribution of shear stress over the wetted perimeter of a meandering open channel is one of the common river engineering problem. It is a key parameter to determine bank erosion and river migration. The influence of turbulence, the secondary flow, the curvature effect, the shape of the cross-section and the boundary condition are some among many technical hitches that are generally related in one way or another to the boundary shear stress making it difficult to analyse. Although some recent works have shed light on the phenomenon of boundary shear distribution, there are still several unexplored aspects that worth consideration.

The research work which is presented in this thesis is an attempt to devise an analytical method, which could compute the average shear stress acting on the bed, inner wall and outer wall of a meandering channel. The attempt relies on splitting the channel cross-section into sub-regions and computing respective hydraulic radii by energy balance method. The concept of energy transportation, well studied, by Einstein (1942) and Yang and Lim (1997) is to be used for first achieving a theoretical basis and then modifying it with perceptive changes to account the curvature of a meandering channel.