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Flow physics in the turbulent near wake of a flat plate

Published online by Cambridge University Press:  08 May 2013

Man Mohan Rai
Man Mohan Rai*
Affiliation:
NASA Ames Research Center, Moffett Field, CA 94035, USA
*
†Email address for correspondence: man.m.rai@nasa.gov
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Abstract

The symmetric near wake of a flat plate with a circular trailing edge, exhibiting pronounced shedding of wake vortices, is investigated via a direct numerical simulation. The separating plate boundary layers are turbulent and statistically identical. The present study focuses on the vortical structures, the distribution of phase-averaged velocity statistics and vorticity fluctuations in the near wake. Braid and vortex core regions are investigated via contours of instantaneous vorticity and pressure with an emphasis on the three-dimensionality of near-wake structures. Rib vortices are observed in the braids. The vortex cores are populated with both ribs that wrap themselves around the cores and spanwise-elongated regions of spanwise vorticity near the centres of the cores. Production terms in the transport equations for phase-averaged fluctuating vorticity show that stretching of rib vortices via the phase-averaged strain rate produces significantly less turbulent vorticity than turbulent stretching in the braids and cores.

JFM classification

Turbulent Flows: Turbulence simulation Vortex Flows: Vortex shedding Wakes/Jets: Wakes
Type
Papers
Information
Journal of Fluid Mechanics , Volume 724 , 10 June 2013 , pp. 704 - 733
Creative Commons
This is a work of the U.S. Government and is not subject to copyright protection in the United States.
Copyright
©2013 Cambridge University Press.

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