Flow Modelling of a Non Prismatic compound channel By Using C .F .D

Abstract

Flooding situation in river is a complex phenomenon and affects the livelihood and economic condition of the region. The modelling of such flow is primary importance for a river engineers and scientists working in this field. Water surface prediction is an important task in flood risk management. As a result of topography changes along the open channels, designing the converging compound channel is an essential. Fluvial flows are strongly influenced by geometry complexity and large overall uncertainty on every single measurable property, such as velocity distribution on different sectional parameters like width ratio, aspect ratio and hydraulic parameter such as relative depth. The geometry selected for this study is that of a non-prismatic compound channel having converging flood plain. For the research work the parameters, the water depth, incoming discharge of the main channel and floodplains were varied. This total topic represents a practical method to predict lateral depth-averaged velocity distribution in a non-prismatic converging compound channel. Then the numerical method is applied to calculate water surface elevation in a non-prismatic compound channel configurations, the results of calculations show good agreement with the experimental data. As numerical hydraulic models can significantly reduce costs associated with the experimental models, an effort has been made through the present investigation to determine the different flow characteristics of a converging compound channel such as velocity distribution, depth averaged velocity distribution, boundary shear etc. In this Thesis a complete three-dimensional and two phase CFD model for flow distribution in a converging compound channel is investigated. The models using ANSYS – FLUENT, a Computational Fluid Dynamics (CFD) code, are found to give satisfactory results when compared to the newly conducted experimental data under controlled system