Numerical solution of depth-averaged velocity and boundary shear stress distribution in converging compound channels

Abstract

In prismatic compound channels, the water level remains uniform throughout the length of the channel. But in case of non-prismatic compound channels, the flow becomes non-uniform and complex. This paper examines the use of Lateral Distribution Method (LDM) and its modifications in the computation of depth-averaged velocity and boundary shear stress distribution in a compound channel for both prismatic and non-prismatic floodplains. The modification of LDM has been done considering the friction slope and secondary current effect. Finite difference scheme has been used for discretizing the Modified LDM using MATLAB tool. For the present study, different prismatic and non-prismatic compound channels having converging flood plains have been considered to evaluate the strength of Modified LDM over other numerical approaches like LDM and Conveyance and Afflux Estimation system.