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The Importance of Secondary Shedding in Two-Dimensional Wake Formation at Very High Reynolds Numbers

Published online by Cambridge University Press:  07 June 2016

P.K. Stansby  and
A.G. Dixon
P.K. Stansby
Affiliation:
Simon Engineering Laboratories, University of Manchester
A.G. Dixon
Affiliation:
Simon Engineering Laboratories, University of Manchester
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Summary

Uncertainties in the use of the discrete-vortex method in modelling the time development of the wake of a circular cylinder at very high Reynolds numbers are investigated. It is shown that simply introducing vorticity at generally accepted separation positions at a rate of ½Us2, Us being the velocity at separation, gives wholly unrealistic wake predictions. In the base region pressure fields occur which would promote separation in steady flow and so a first approximation for ‘secondary’ separation is incorporated into the model. This brings pressure distributions and vorticity structures at subcritical and supercritical Reynolds numbers into good agreement with experiment. The convection of the vortices is calculated using the cloud-in-cell technique and comparisons are made with direct summation methods.

Type
Research Article
Information
Aeronautical Quarterly , Volume 33 , Issue 2 , May 1982 , pp. 105 - 123
Copyright
Copyright © Royal Aeronautical Society. 1982

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References

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