FLOW ANALYSIS IN COMPOUND OPEN CHANNEL FLOW USING ANSYS

Abstract

Flooding in Indian rivers is a very serious problem which affects the livelihood and financial condition of that place. This problem has been identified by many Researchers like Tominaga and Nezu , Ackers and V.T Chow. A lot of research work has been devoted to find out desirable solution of flooding problem. While flooding, river flows with high discharge which overflows on its banks and excess water reaches to its flood plains, this excess water leads to formation of compound channel. The nature of flow during flooding is generally turbulent in nature. It has been found that the velocity of flow in flood plain is less than the velocity of flow in main regular channel. It is a well known fact that this change in velocity leads to formation of a shear layer. These shear layers produce resistance to flow, which leads to uncertainty in forecasting of flow and also increases resistance on channel. Geometric similar model can be utilized to find out necessary information. Generally one dimensional empirical model can be used to forecasting of flow taking assumption that flow is uniform in compound channel. However, Compound open channel has partially uniform flow due to momentum transfer in sub sections and unexpected change in depth of flow. Hence the analysis of turbulent flow is necessary in this situation. In Past, researchers have used various models to analyze turbulent flow in compound open channels, basically for low development length. Hence, in this study an effort is made to analyze the turbulent flow by Large Eddy Simulation method (LES) to forecast the flow and its resistance on channel. The LES is carried out by taking sufficient development length so that uniform turbulent flow can be developed. The development length is incorporated in the computational domain. It is fact that experimentally flow analysis of compound open channels with various hydraulic conditions is very expensive and difficult. Hence, this analysis of flow is done by using software approaches such as used in Ansys Software.