Depth-Averaged Velocity Distribution for Symmetric and Asymmetric Compound Channels

Abstract

Movement of water during flood creates a compound channel appearance which consists of a main channel and its adjoining floodplains are very important for environmental, ecological and design issues. The structures of the flow in such channels are rigorous. The principal reason of this flow structure is due to the momentum transfer mechanism between the main channel and the floodplain. Flow mechanism in an asymmetric compound channel is different than that of a symmetric compound channel. There is a stronger interaction exists between the main channel and floodplain in asymmetric compound channel as compared to symmetric compound channel where the interaction is distributed to the both sides of the floodplain. Analysis of depth-averaged velocity distribution in both compound channels is strongly influenced by width ratio, aspect ratio and relative flow depth. The variation of depth-averaged velocity distribution in such channels for different geometry and flow conditions has been analysed. Proper prediction of depth-averaged velocity distribution in a compound channel is depending upon the magnitude of shear layer for which the advanced software CES is not providing accurate prediction especially for asymmetric compound channel. Suggestions and improvements to predict depth-averaged velocity distribution in both symmetric and asymmetric compound channels have been made.