Vortex Transport in Separating flows and Role of Vortical Structures in Reynolds Stress Production and Distribution

Yazdani, M ; Sharif University of Technology | 2005

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  1. Type of Document: Article
  2. DOI: 10.1115/FEDSM2005-77005
  3. Publisher: 2005
  4. Abstract:
  5. In this paper we will present some approaches on Reynolds stress production by vortex transport phenomena and nonlinear voracity generation in momentum equation. First of all we represent a history of recent works to describe how fluid particle motions can be associated with Reynolds stress through either displacement or acceleration terms. In the next section we will describe how vortex stretching causes the Reynolds stress production and what is the dominant effect near and far from the boundary where viscous effects have to be considered. On the other hand, some vortex considered methodologies such as those synthesize boundary layer, as a collection of vortical objects seem to be inappropriate in general flow configuration. Therefore, there must be a moderate consideration in which both vortex and momentum transports come into account as it is done in LES. Furthermore since there exist open questions on Reynolds stress distribution in complex flows such as those with separation, our particular attention is paid to such effects due to vortical structures in separating flows. Further discussions include turbulence development caused by either vortex stretching or gradient terms that is determined by predominant conditions. However, it is seen that at the beginning, vorticity generators in Navier-Stokes equation contribute to dissipation effect. In addition, since such contribution corresponds to vorticity alignment, we investigate maximum vortex aligning and the effects of which causes the deviation of such alignment. The paper provides theoretical and numerical comparisons, where in the former, the vortical structure role is taken into account. Copyright © 2005 by ASME
  6. Keywords:
  7. Complex flows ; Fluid particle motions ; Reynolds stress ; Vortex transport ; Acceleration ; Boundary layers ; Nonlinear equations ; Numerical analysis ; Reynolds number ; Vortex flow
  8. Source: 2005 ASME Fluids Engineering Division Summer Meeting, FEDSM2005, Houston, TX, 19 June 2005 through 23 June 2005 ; Volume 2005 , 2005 , Pages 11-18 ; 0791837602 (ISBN); 9780791837603 (ISBN)
  9. URL: https://asmedigitalcollection.asme.org/FEDSM/proceedings-abstract/FEDSM2005/41987/429/312763?redirectedFrom=PDF