|June 22, 2012, 07:08||
Questions about inlet extension
Join Date: Jun 2012
Posts: 98Rep Power: 6
It happens a lot that we extend the inlet or the outlet when we do a simulation.
Because of that we can get reasonable velocity profile.
But when i set pressure inlet condition,does the extension make sense?
What is the exact reason that we extend the inlet or outlet.
I hope i am clear.
|June 23, 2012, 06:41||
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 12,638Rep Power: 98
We extend the inlet or outlet because the boundary conditions are most accurate (and numerically stable) when the flow crosses the boundary perpendiculat and with zero (or low) normal gradient. When the boundary is too close it might cut recirculations and other complex flow features and the boundary will not accurately model a separation cut in two.
But you have raise an important point - if you extend the boundary and it is a pressure boundary then you may have additional viscous pressure loss, so you may have to offset the pressure to account for this.
|Thread||Thread Starter||Forum||Replies||Last Post|
|ATTENTION! Reliability problems in CFX 5.7||Joseph||CFX||14||April 20, 2010 15:45|
|Problems with Inlet species||San24||CD-adapco||1||May 7, 2008 06:29|
|questions in initial conditions and inlet boundary||nick||CFX||2||April 19, 2008 09:26|
|UDF problem : inlet velocity in cyl. coord. system||Jongdae Kim||FLUENT||0||June 15, 2004 11:21|
|length scales at inlet for internal flows||Anne-Marie Giroux||Main CFD Forum||3||July 5, 1999 21:28|