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Old   December 3, 2007, 07:00
Default LES
  #1
John Deas
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I would like to study decay of vortices structures behind a vortex generator at Re_bulk=5000 in a plain channel, isn't LES a bit of an overkill there ?
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Old   December 3, 2007, 18:27
Default Re: LES
  #2
pankaj saha
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hi, i also work on LES. But what exactly, your problem is? Can you tell?
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Old   December 4, 2007, 08:51
Default Re: LES
  #3
John Deas
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I would like to quantify the viscous dissipation of the structures behind the winglet and link it with the heat transfer. I would like to compare stationnary RANS and non stationnary calculations.
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Old   December 4, 2007, 18:00
Default Re: LES
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pankaj saha
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which type of winglet u are using...delta wing or winglet pair....Which paper you would like to compare , related to RANS?
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Old   December 7, 2007, 00:37
Default Re: LES
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If I understant correctly, your Re_bulk is not very high. Can you not attempt a DNS? If DNS resolution requirements are too high, I think attempting LES is quite reasonable. If you could explain why you think LES for this is an overkill, I might be able to explain better.

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Old   December 7, 2007, 04:37
Default Re: LES
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John Deas
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I want mainly to compare with "Heat transfer in a rectangular channel with a vee-shaped vortex generator" by Sohankar. However, I have a single delta winglet while he have two. He uses dns and LES, and found the results comparables.
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Old   December 7, 2007, 04:38
Default Re: LES
  #7
John Deas
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I thought LES was interesting for high Reynolds numbers (more than 10000), but for less, RANS and URANS might be sufficient.
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Old   December 7, 2007, 18:08
Default Re: LES
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Yes that is correct. So, with the present computational power, computing DNS for your case should not be much effort, don't you think?
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Old   December 25, 2007, 17:18
Default Re: LES
  #9
pankaj saha
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hi, For the winglet problem....Do, anyone need to satisfy Y+=1 around the winglet body also? as near the wall it must be a criterion for les? Can anyone tell what is the reason?
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