Distance to oulet

Mankim · May 31, 2010, 08:01

Does anyone have a rule of thumb on how far you should have between your region of interest and the outlet boundary to be sure that you do not suffer from effects imposed by the BC?

I understand that this is a function of Re or flow velocity but how and what more?

I am considering pipe flow myself but I would like to hear any thoughts on this.

Jonas Holdeman · May 31, 2010, 10:10

This depends greatly on the method used. I have computed flow over a backwards-facing step, Re=800, with the mesh truncated through the recirculation with error of a few percent compared with an extended mesh. See the link below.

http://webpages.charter.net/jtholdeman/RevIJNMFart1.pdf

May 31, 2010, 08:01	Distance to oulet	#1
Mankim New Member David Mauritzson Join Date: Oct 2009 Posts: 2 Rep Power: 0	Does anyone have a rule of thumb on how far you should have between your region of interest and the outlet boundary to be sure that you do not suffer from effects imposed by the BC? I understand that this is a function of Re or flow velocity but how and what more? I am considering pipe flow myself but I would like to hear any thoughts on this.

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May 31, 2010, 10:10		#2
Jonas Holdeman Senior Member Jonas T. Holdeman, Jr. Join Date: Mar 2009 Location: Knoxville, Tennessee Posts: 128 Rep Power: 18	This depends greatly on the method used. I have computed flow over a backwards-facing step, Re=800, with the mesh truncated through the recirculation with error of a few percent compared with an extended mesh. See the link below. http://webpages.charter.net/jtholdeman/RevIJNMFart1.pdf