# periodic boundary condition in LES

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 September 4, 2009, 06:36 periodic boundary condition in LES #1 New Member   Maria Torres Join Date: Sep 2009 Posts: 1 Rep Power: 0 Hey, I am currently performing LES for turbulent channel flow at a reynolds number of 10935 using FLUENT. I have two questions: - Can i specify in FLUENT periodic boundary condition in streamwise and spanwise simultaneously ? How can i do this? -Can I specify the shear stress as wall boundary condiction with the periodic pressure gradient in the streamwise direction? Thanks in advance Marķa jzc likes this.

 April 9, 2012, 20:28 #2 Member   Negin Nazarian Join Date: Jan 2012 Location: San Diego Posts: 61 Rep Power: 14 Hi I was wondering if you found the answer to your first question. Thanks Negin

 April 10, 2012, 19:17 #3 Senior Member   Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,679 Rep Power: 66 You can do periodic boundary conditions in streamwise and spanwise conditions simultaneously. It is possible, I have done this. It is straightforward. Just make the planes periodic (you need to do this using the TUI, it cannot be done with GUI commands). I do not think that specifying the wall shear stress is appropriate, especially for LES. You would need to know the local wall shear stress everywhere on the walls and apply that as a boundary condition through UDF (which means you would have to already know what the flow looks like, which means that you have already solved your problem, which means that you do not need to do any LES). villager likes this.

April 30, 2022, 00:20
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Tom O
Join Date: Mar 2022
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Quote:
 Originally Posted by LuckyTran You can do periodic boundary conditions in streamwise and spanwise conditions simultaneously. It is possible, I have done this. It is straightforward. Just make the planes periodic (you need to do this using the TUI, it cannot be done with GUI commands). I do not think that specifying the wall shear stress is appropriate, especially for LES. You would need to know the local wall shear stress everywhere on the walls and apply that as a boundary condition through UDF (which means you would have to already know what the flow looks like, which means that you have already solved your problem, which means that you do not need to do any LES).
Hi

I was wondering if you make the planes periodic by using the TUI，can streamwise and spanwise conditions set flow rate or pressure drop respectively？

OYYO