Impact of Geometry on Flow Characteristics Inside River Intakes

Document Type : Original Article

Authors

1 Benha University, Egypt

2 National Water Research Center, Egypt

3 Hydraulics Research Institute, Egypt

Abstract

Intake is an open channel that usually has a non-uniform flow along its length. The pattern of the flow in lateral intakes is fully three-dimensional. Velocity and direction change in lateral intakes lead to non-consistency and recirculation of the flow. As the result of these whirlpools, depositions are accumulated inside intakes which consequently decrease intake efficiency. High maintenance cost is regularly paid in order to dredge the sedimentation areas and to guarantee and maintain efficiency. The aims of this study were to get a suitable design of the lateral intakes. This study is conducted by using a numerical Software Delft3D-FM which used in predicting flows pattern. These patterns are validated and employed in a parametric study. In this study, four models with sharp edges and different bed levels were presented to investigate flow separation zones at different angles of the intake entrance. Comparisons between the predicted and the initial configuration velocities at the considered sections indicate that the model captures most of the trends with sensible accuracy. It is concluded that configuration 4 which has two-fold baffle walls located on the right side has a significant effect on improving flow velocity, circulation zone length, reverse flow width as it enforces the flow to the inner side achieving a good flow distribution inside the intake. The results indicate also that the optimal angle of lateral intake which gives minimum length and width of separation zone is at θ = 30o.

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