Boundary layer discretization

Andrey82 · September 5, 2021, 17:30

Hello! I have a question about Two-Scales Wall Functions. Specifically, I am interested in the question of where the center of the first cell is allowed to be located. Did I do it correctly in the screenshot? If you recommend literature about Two-Scales Wall Functions, I would be grateful.
https://pastenow.ru/DRXVV

Boris_M · October 6, 2021, 03:08

Hi Andrey,

the two-scale wall function is automatically choosing which method is being used depending on the mesh resolution of the boundary layer.
So if the mesh is too coarse, the one model is used and if fine enough, the other one is used. You can find more information on the two models (thin and thick boundary layer, with respect to the mesh resolution) in the Technical References document that is installed with the software. simply type in the Start menu of Windows "Technical Reference" and it will show you either a PDF document or an HTML file for the newer versions of Simcenter FLOEFD.

The center of the first cell depends on the mesh of course. You can have the cell being split by into two or more control volumes by some intersecting solid and then the center of the first fluid cell is in the center of that control volume of the fluid part of the cell.

May I ask why you are trying to dig that deep into where the center is etc.?
Is this a research project or do you want to validate the result accuracy of Simcenter FLOEFD?

Regards,
Boris

September 5, 2021, 17:30	Boundary layer discretization	#1
Andrey82 New Member Andrey Join Date: Sep 2021 Posts: 1 Rep Power: 0	Hello! I have a question about Two-Scales Wall Functions. Specifically, I am interested in the question of where the center of the first cell is allowed to be located. Did I do it correctly in the screenshot? If you recommend literature about Two-Scales Wall Functions, I would be grateful. https://pastenow.ru/DRXVV

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October 6, 2021, 03:08		#2
Boris_M Disabled Join Date: Jul 2009 Posts: 616 Rep Power: 23	Hi Andrey, the two-scale wall function is automatically choosing which method is being used depending on the mesh resolution of the boundary layer. So if the mesh is too coarse, the one model is used and if fine enough, the other one is used. You can find more information on the two models (thin and thick boundary layer, with respect to the mesh resolution) in the Technical References document that is installed with the software. simply type in the Start menu of Windows "Technical Reference" and it will show you either a PDF document or an HTML file for the newer versions of Simcenter FLOEFD. The center of the first cell depends on the mesh of course. You can have the cell being split by into two or more control volumes by some intersecting solid and then the center of the first fluid cell is in the center of that control volume of the fluid part of the cell. May I ask why you are trying to dig that deep into where the center is etc.? Is this a research project or do you want to validate the result accuracy of Simcenter FLOEFD? Regards, Boris