Vortex Method in Fluent LES

tengf689 · February 24, 2017, 03:46

Hi all
I wanna simulate the flow around a cube by using Fluent LES . I know that it is necessary to set fluctuations at Inlet. Now I have some questions:
If I use "vortex method" to generate fluctuations at inlet, how could I give the "Number of Vortices"? (By default, the number of vortices is 190). And how this value influence the result?
By the way , the version of my Fluent is 17.2
Thanks

kingjewel1 · April 16, 2018, 09:42

Hello,

Good question. I read in one of ANSYS' LES solution guides that the number of vortices should be N/4 where N=number of inlet grid cells. But how this influences the solution, I'm not sure. Any further thoughts?

u2berggeist · October 2, 2018, 10:19

Do you remember what LES solution guide you saw this in kingjewel1?

kingjewel1 · October 2, 2018, 10:39

Quote:

Originally Posted by u2berggeist

Do you remember what LES solution guide you saw this in kingjewel1?

Hi,

Yes it's in "Quick Guide to Settings UP LES-type Simulations" in the ANSYS customer portal Solution: 2039348.

Also here: http://www.tfd.chalmers.se/~lada/com...4_for_Lars.pdf

u2berggeist · October 2, 2018, 18:18

Thanks!

Since we're posting relevant references, here's a paper I found that goes over the application of VM.

Interesting point, the "Methodology" section of the paper is word-for-word identical to the ANSYS documentation. The lead writer of the paper worked at Fluent, which explains it, but is still pretty unethical (plagiarism does include reproducing your own work with out reference).

February 24, 2017, 03:46	Vortex Method in Fluent LES	#1
tengf689 New Member FeiTeng Join Date: Jan 2017 Location: Beijing,China Posts: 12 Rep Power: 9	Hi all I wanna simulate the flow around a cube by using Fluent LES . I know that it is necessary to set fluctuations at Inlet. Now I have some questions: If I use "vortex method" to generate fluctuations at inlet, how could I give the "Number of Vortices"? (By default, the number of vortices is 190). And how this value influence the result? By the way , the version of my Fluent is 17.2 Thanks

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April 16, 2018, 09:42		#2
kingjewel1 Senior Member Join Date: Jul 2009 Posts: 260 Rep Power: 17	Hello, Good question. I read in one of ANSYS' LES solution guides that the number of vortices should be N/4 where N=number of inlet grid cells. But how this influences the solution, I'm not sure. Any further thoughts?

October 2, 2018, 10:19		#3
u2berggeist Member James Wright Join Date: Oct 2015 Posts: 40 Rep Power: 10	Do you remember what LES solution guide you saw this in kingjewel1?

October 2, 2018, 18:18		#5
u2berggeist Member James Wright Join Date: Oct 2015 Posts: 40 Rep Power: 10	Thanks! Since we're posting relevant references, here's a paper I found that goes over the application of VM. Interesting point, the "Methodology" section of the paper is word-for-word identical to the ANSYS documentation. The lead writer of the paper worked at Fluent, which explains it, but is still pretty unethical (plagiarism does include reproducing your own work with out reference).