CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   Main CFD Forum (https://www.cfd-online.com/Forums/main/)
-   -   LES (https://www.cfd-online.com/Forums/main/14466-les.html)

John Deas December 3, 2007 07:00

LES
 
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 ?

pankaj saha December 3, 2007 18:27

Re: LES
 
hi, i also work on LES. But what exactly, your problem is? Can you tell?

John Deas December 4, 2007 08:51

Re: LES
 
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.

pankaj saha December 4, 2007 18:00

Re: LES
 
which type of winglet u are using...delta wing or winglet pair....Which paper you would like to compare , related to RANS?

agg December 7, 2007 00:37

Re: LES
 
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.


John Deas December 7, 2007 04:37

Re: LES
 
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.

John Deas December 7, 2007 04:38

Re: LES
 
I thought LES was interesting for high Reynolds numbers (more than 10000), but for less, RANS and URANS might be sufficient.

agg December 7, 2007 18:08

Re: LES
 
Yes that is correct. So, with the present computational power, computing DNS for your case should not be much effort, don't you think?

pankaj saha December 25, 2007 17:18

Re: LES
 
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?


All times are GMT -4. The time now is 08:11.