All the data and graphs on this page are obtained for a Channel flow $ Re_\tau = 395 $, where inlet condition are generated by using different methods and imposing as velocity/Reynolds stresses profiles Moser and alt. DNS data!

PAPER tex and pdf

Here you are the links to the tex file tsfp_paper_final.tex and to the pdf tsfp_paper_final.pdf of

the paper (obviously they are still only drafts!!!!)!! I have uploaded the summary page as well!SummaryTSFP.pdf

NOTE: CHECK OUT THIS PAGE FOR THE 2DHUMP RESULTS!!!

Comparison

CfcomparisonDNS.png

CF of DF-SEM with sigma and Rey obtained at cells center!

Cf_solo.png

Cf_solo_final.png

Applied ReyStress

eigvalue.pngreystresses.png

In case of a redistribution only among uu and vv:

appliedreynolds.png

uv is again under-estimated because:

$ uv = \lambda_1 r_{11} r_{12} + \lambda_2 r_{21} r_{22} $

where $ r_{11} r_{12} = - r_{21} r_{22} = \alpha $.

When $ \lambda_{i} $ is rescaled we have: $ \lambda_{1r} = \lambda_{1} - \beta $ and $ \lambda_{2r} = \lambda_{2} + \beta $.

The new uv is then:

$ uv = \lambda_{1r} r_{11} r_{12} + \lambda_{2r} r_{21} r_{22} = (\lambda_{1} - \beta) \alpha + (\lambda_{2} + \beta) (-\alpha) = uv - 2 \beta \alpha $

The simulation did not show any improvement respect to the ones where the redistribution of the kinetic energy involves all the directions!

It is then impossible to obtain the same level of shear stress without changing the turbulent kinetic energy! At the moment I am trying to run a simulation where, with a different turbulent kinetic energy, I manage to reproduce exactly the shear stress!

Update: after a while I managed to demonstrate that in our conditions (decrease the value of one normal stress and increase all the others) it is impossible to keep constant the shear stress, even in a 2D problem!

The last interesting simulation that I am running at the moment is the one with the following ReyStress :

reystress_vv.png

DF-SEM

VelProfDFSEMx_0.0.pngVelProfx_0.0DFSEMr.pngk_budgetepDFSEMx_0.0.pngkbudgetprDFSEMx_0.0.png

TurbProfx_0.0DFSEMr.png UVProfx_0.0DFSEMr.png

SEM

TurbProfx_0.0SEMr.png UVProfx_0.0SEMr.png

Vortex (Sergeant)

TurbProfx_0.0VORTEX.png UVProfx_0.0VORTEX.png

Energy Spectrum (Davidson)


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Topic attachments
I Attachment Action Size Date Who Comment
pdfpdf SummaryTSFP.pdf manage 343.8 K 2011-04-26 - 11:02 RuggeroPoletto  
pdfpdf tsfp_paper_final.pdf manage 644.7 K 2011-05-05 - 14:56 RuggeroPoletto  
elsetex tsfp_paper_final.tex manage 29.8 K 2011-05-05 - 14:48 RuggeroPoletto  
pdfpdf tsfp_template.pdf manage 522.8 K 2011-04-27 - 14:15 RuggeroPoletto  
elsetex tsfp_template.tex manage 27.3 K 2011-04-27 - 14:16 RuggeroPoletto  
Topic revision: r19 - 2011-05-05 - 14:56:44 - RuggeroPoletto
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