ePrints@IIScePrints@IISc Home | About | Browse | Latest Additions | Advanced Search | Contact | Help

Numerical Investigation of Centrifugal Instability Around a Circular Cylinder Rotated Impulsively

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.

[img] PDF
prabhu2015.pdf - Published Version
Restricted to Registered users only

Download (585kB) | Request a copy
Official URL: http://dx.doi.org/10.1142/9789814635165_0012

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
Additional Information: Copyright 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: 19 Jul 2019 17:33
URI: http://eprints.iisc.ac.in/id/eprint/55046

Actions (login required)

View Item View Item