Investigation on the Critical Froude Number at the upstream of Local Side Contraction in a Dam Reservoir with Linear Stratification.

Document Type : Research Article


1 m.Sc. of Water Engineering, Sharif University of Technology, Tehran, Iran.

2 Associate Professor, Civil Engineering Department, Sharif University of Technology, Tehran, Iran.


Knowledge of technique of selective withdrawal is important in environmental hydrodynamic studies of dam reservoirs. The technique is used to obtain water of desired quality for drinking, industrial, and agricultural purposes, and is a water quality management tool of reservoirs.
Considering the importance of the reservoir topography in selective withdrawal, in this paper the effects of side contraction on selective withdrawal of linearly stratified water from a point and a line sink in a reservoir is studied using Particle Image Velocimetry. The effects of contraction on propagation of shear waves and withdrawal layer thickness are discussed and the obtained critical Froude number is compared with the previous studies. The results show that the description of selective withdrawal in terms of motion of shear waves through contraction is a suitable method for predicting the critical Froude number.


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