Turbulence, instabilities and passive scalars in rotating channel flow
Brethouwer G, Schlatter P, Johansson AV (2011)
Publication Type: Conference contribution
Publication year: 2011
Publisher: Institute of Physics Publishing
Book Volume: 318
Conference Proceedings Title: Journal of Physics: Conference Series
Event location: POL
DOI: 10.1088/1742-6596/318/3/032025
Abstract
Fully developed channel flow with a passive scalar rotating about the spanwise axis is studied by direct numerical simulations. The Reynolds number based on the bulk mean velocity Reb is up to 30000, substantially higher than in previous studies, and the rotation rates cover a broad range. Turbulence on the stable channel side is less strongly damped at moderate rotation rates than in channel flow at lower Reb. At high rotation rates and sufficiently high Reb, intermittent strong instabilities occur on the stable side caused by rapidly growing modes resembling two-dimensional Tollmien-Schlichting waves which at some instant become unstable and break down into intense turbulence. The turbulence decays and after some time the waves form again and the process is repeated in a cyclic manner. Rotation also strongly affects the mean passive scalar profiles and turbulent scalar fluxes. Large scalar fluctuations are observed on the border between the stable and unstable channel sides. While in non-rotating channel flow the turbulent Prandtl number of the passive scalar is about one like in other shear flows, it is much smaller in the rotating cases.
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How to cite
APA:
Brethouwer, G., Schlatter, P., & Johansson, A.V. (2011). Turbulence, instabilities and passive scalars in rotating channel flow. In Journal of Physics: Conference Series. POL: Institute of Physics Publishing.
MLA:
Brethouwer, Geert, Philipp Schlatter, and Arne V. Johansson. "Turbulence, instabilities and passive scalars in rotating channel flow." Proceedings of the 13th European Turbulence Conference, ETC13, POL Institute of Physics Publishing, 2011.
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