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abdul moqeet January 26, 2011 02:54

boundary conditions
Dear All,

i am new to cfd. in my MSc project i have to use cfd as a tool. air is to be simulated in a rectangular pipe, suction of air is taking place at outlet or exit. only the air velocity is known in the pipe. tell me about the boundary conditions which i should use for this suction at outlet case????? thanks in advance


RossFS January 28, 2011 21:11

Just set the exit pressure and maybe a mass flow rate?
The specific name of the boundary condition would depend on the software you are using(?)

abdul moqeet January 29, 2011 07:48


i'm using fluent 6.3.26. currently i'm using velocity inlet boundary condition, so in result the standard deviation of velocity at the inlet face is minimum and std dev of velocity at the outlet is maximum. but it will not be true in orignal case as suction is at outlet so std deviation of velocity at oulet face should be minimum...
please guide
i look forward for your response

RossFS January 30, 2011 03:31

I'd say that the tighter boundary conditions would need to be set at the suction end.
The best way to work out what settings you should use at either end is to check out the user guide for Fluent (user_guide.pdf I think) in the Fluent installation directory. The guide is >= 1000 pages in length and appeared to be well written in the bit I looked at. This document will give you detailed descriptions of the boundary conditions that you can set in Fluent and the conditions that they are suited to modelling.

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