Flow Transition Due to Width Contraction

Abstract

This study analyses an open channel flow’s transition due to contraction of width. The flow is initially subcritical (i.e. Fr < 1). Comparison between theoretical and experimental study is done to analyse the minimum contracted width such that if the width of the downstream section is more than this minimum contracted width flow can take place without any change in upstream specific energy. The abbreviated term suggests that the width of the open channel decreases and that leads to changes in the flow values of the differentiation from the others produced above. The dimensions of many water streams, which satisfy proper hydraulic conditions, may not be compatible with the designed dimensions of an irrigation work that needs to be constructed in some locations. The design requirements of such irrigation works may involve a contraction in the channel width in the required location. Then 2 models are prepared on ANSYS fluent one having width 0.190m which is more than the minimum contracted width and other having width of 0.1m which is less than minimum contracted width. Then the results are presented in the form of contours of volume fraction on the wall of model which validates the theoretical changes in upstream and downstream depths of flow in each case.