Evaluation of Zero Shear Interface Methods in an Asymmetric Compound Channel

Abstract

In a compound channel, due to strong interaction between the main channel and floodplain flows, the apparent shear stress at different interfaces of the compound sections varies greatly. River channels are often flanked by either side flood plain which is known as asymmetrical compound channel. There are many reports found in literature related to compound channels with symmetrical flood plains and very few are found for asymmetrical cases. In a symmetrical compound channel the transfer of momentum occurs from both sides of the channel to the flood plains uniformly. In case of a compound channel with asymmetrical floodplain, there is a stronger interaction between main channel and flood plains occur as compared to the symmetrical case. Many investigators have studied and modeled in predicting the flow variables of the compound channel which are generally applicable for symmetrical cases. In this paper, some approaches for predicting flow using different area methods in asymmetric channels are described. On the basis of multi linear regression analysis, an improved area method has been proposed. The proposed method is successfully validated to the experimental data and the flood channel facilities of UK data and the merits and demerits of the proposed method with other discussed methods have been done. The comparisons of these methods to different flow conditions are outlined using error analysis.