Question about outlet boundary condtion settting for transitional model

Anna Tian · March 3, 2013, 13:45

Hi,

When I use the transitional model (Gamma Theta Model), I need to set up the turbulence intensity at the outlet boundary conditions. I'm confused about how do I know it before I simulate it?

Thanks!

ghorrocks · March 3, 2013, 16:55

You do not specify the turb intensity at outlets. Obviously the turbulence just exits the domain and plays no role in the simulation. Why do you want to specify the turbulence at the outlet?

If you change the outlet to an opening, this will allow back flow and then you will need to specify the conditions of the back flow fluid including turbulence intensity.

Anna Tian · March 3, 2013, 18:35

Quote:

Originally Posted by ghorrocks

You do not specify the turb intensity at outlets. Obviously the turbulence just exits the domain and plays no role in the simulation. Why do you want to specify the turbulence at the outlet?

If you change the outlet to an opening, this will allow back flow and then you will need to specify the conditions of the back flow fluid including turbulence intensity.

Thank you very much! Yes. I set it as opening.

March 3, 2013, 13:45	Question about outlet boundary condtion settting for transitional model	#1
Anna Tian Senior Member Meimei Wang Join Date: Jul 2012 Posts: 494 Rep Power: 15	Hi, When I use the transitional model (Gamma Theta Model), I need to set up the turbulence intensity at the outlet boundary conditions. I'm confused about how do I know it before I simulate it? Thanks! __________________ Best regards, Meimei

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March 3, 2013, 16:55		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	You do not specify the turb intensity at outlets. Obviously the turbulence just exits the domain and plays no role in the simulation. Why do you want to specify the turbulence at the outlet? If you change the outlet to an opening, this will allow back flow and then you will need to specify the conditions of the back flow fluid including turbulence intensity.