Experimental Study of Velocity and Concentration Profiles of Density Current in a 90 Degree Bend

Document Type : Research Paper

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Abstract

Density currents are formed due to gravity face action on the two fluids with different densities. This paper investigates the effect of radius of stream route curvature on the velocity and concentration profiles in density current. Experiments were conducted in a flume with three different curvature radii of 40, 80 and 120 cm. Acoustic Doppler velocity meter was used to record the instantaneous downstream (u), cross stream (v) and vertical flow (w) velocities. Before entering the bend, the flow is longitudinal. In open-channel bends, surface flow moves towards the outer bank and the flow on the floor moves towards the inner bank. Results showed that in density current the maximum stream wise velocity occured near the stream bed. Due to density stratification, in addition to the difference in height, generated pressure difference force was not constant throughout the depth of a density current and depended on reduced gravity and Concentration profile of flow. As a result, lateral flow reversed and near-bed flow towarded the outer bank. With increasing the radius of the flume curvature, circulation cell became poor and smaller.

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Water and Soil Science
Volume 27, Issue 1
June 2017
Pages 69-82

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