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Waves from an oscillatory disturbance in a stratified shear flow

Published online by Cambridge University Press:  26 April 2006

R. Liu ,
D. Nicolaou  and
T. N. Stevenson
R. Liu
Affiliation:
Department of Engineering, University of Manchester, Oxford Road, Manchester M13 9PL, UK
D. Nicolaou
Affiliation:
Department of Engineering, University of Manchester, Oxford Road, Manchester M13 9PL, UK
T. N. Stevenson
Affiliation:
Department of Engineering, University of Manchester, Oxford Road, Manchester M13 9PL, UK
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Abstract

It is shown how the St Andrew's cross-wave in a density-stratified fluid is modified by a horizontal shear above the level of the source. Ray theory is used to develop the equations for the phase configuration and it is shown that, for the special case when the background natural frequency is constant and the shear is linear, the wave crests are straight lines passing through the source. The waves corresponding to outgoing energy have phase velocities directed towards the horizontal level of the source and the waves which have undergone a reflection have phase velocities directed towards the vertical. It is shown that the ray theory predictions compare well with experiment and with finite-difference calculations.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 219 , October 1990 , pp. 609 - 619
Copyright
© 1990 Cambridge University Press

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