Prabhu, Akhilesh M and Shukla, Ratnesh K and Arakeri, Jaywant H
(2016)
*Numerical Investigation of Centrifugal Instability Around a Circular Cylinder Rotated Impulsively.*
In: IUTAM Symposium on Advances in Computation, Modeling and Control of Transitional and Turbulent Flows, DEC 15-18, 2014, Goa, INDIA, pp. 146-154.

## Abstract

The inception and growth of centrifugally driven instabilities around an impulsively rotated cylinder is investigated through direct numerical simulations. Full three-dimensional simulation at a Reynolds number (Re) of 200, shows that the initial instability manifests as axisymmetric toroidal vortices stacked periodically along the cylinder axis. Based on this finding, two-dimensional axisymmetric simulations are performed for Reynolds numbers spanning seven orders of magnitude. A critical wavelength lambda(c), defined as the wavelength of the first unstable mode is calculated over a range of Reynolds numbers based on the cylinder radius and wall velocity. A critical boundary layer thickness delta(c) is defined based on vorticity and is found to scale as Re-2/3 at large Reynolds numbers. The critical wavelength.c exhibits a similar scaling, so that lambda(c) similar to delta(c) for Re >> 1. A Taylor number based on the wavelength of the instability as the characteristic length scale is defined and its variation with the Reynolds number is discussed.

Item Type: | Conference Proceedings |
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Additional Information: | Copy right for this article belongs to the WORLD SCIENTIFIC PUBL CO PTE LTD, PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE |

Department/Centre: | Division of Mechanical Sciences > Mechanical Engineering |

Depositing User: | Id for Latest eprints |

Date Deposited: | 22 Oct 2016 09:33 |

Last Modified: | 22 Oct 2016 09:33 |

URI: | http://eprints.iisc.ac.in/id/eprint/55046 |

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