Application of the Shiono and Knight Method in compound channels with non-prismatic floodplains

Abstract

The Shiono and Knight Method (SKM) is known as a capable tool to model flow in prismatic compound channels. This research explores whether SKM can be used to predict depth-averaged velocity and boundary shear stress in compound channels with non-prismatic floodplains. For this reason SKM was modified and used in combination with an extensive experimental data set of depth-averaged velocity and boundary shear stress measurement to investigate the issue over three various floodplain converging angles and relative depths. The modeling results indicate a good agreement between the experimental data and the modified SKM. Also, based on the momentum balance and using the experimental data on compound channel with non-prismatic floodplains lateral variations of the depth-averaged apparent shear stress, the Reynolds shear stress, and the secondary flow were investigated. The results reveal that the Reynolds shear stress is significant at the interface between the main channel and floodplains and secondary flow has linear variation.