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Rotational channel flow over small three-dimensional bottom irregularities

Published online by Cambridge University Press:  29 March 2006

Jørgen Fredsøe
Jørgen Fredsøe
Affiliation:
Institute of Hydrodynamics and Hydraulic Engineering, Technical University of Denmark, DK 2800 Lyngby/Copenhagen
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Abstract

Rotational flow of an inviscid fluid over an irregularity in the bottom is investigated. The flow is regarded as a perturbed unidirectional flow, and the shape of the irregularity is described using Fourier transforms. The velocity profile in the unidirectional flow is determined using the eddy-viscosity concept and a finite wall slip velocity.

Two different examples of irregularities are considered: (a) an infinitely long straight irregularity which forms an arbitrary angle with the direction of the basic flow and (b) a hump in a channel with impermeable walls. The influence of rotation on the two- and three-dimensional waves which are formed downstream of these irregularities is analysed and experimentally verified. Further, it is shown that the gradient of the basic velocity profile increases the transverse movement of the fluid particles at the bottom, while at the surface this transverse movement is decreased.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 66 , Issue 1 , 21 October 1974 , pp. 49 - 66
Copyright
© 1974 Cambridge University Press

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