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Janshi August 16, 2010 09:06

Boundary Conditions: Non constant flow pattern / temperature profil

First at all, please allow me to introduce myself. My name is Shichun and Im working on my Mastertheses.

Currently Im looking for a possibility to simulate the Mixture of two Gasflows.
I have a Combustion in a Tube. Through researches with Thermocouples I know the temperature profil from my flue gas.
The flue gas shall enter an "object", where it is mixed with Air.
It seems that I have a basic problem.
I have to define the boundary conditions at the Inlet for the "object".
So how can I tell FLoEFD that I have a non constant flow pattern/velocity profile and temperature profil of my flue gas at the inlet of my "object"?



Boris_M September 1, 2010 02:56

Hi Shichun,

I hope it's not too late already but here is the way to do it.
In the boundary settings for pressure or flow rates you can vary the pressure and flow rates either over time or over a coordinate such as x, y, z or the radius etc. You cannot define a distribution on a surface in two coordinates, just one f(x) or f(y) etc. is possible.
You can define it as a grah like the fully developed flow profile of a pipe with f(r) or you can define it with a function. The same goes for transient analysis f(t) or as a pulsation defined with a function such as 5*sin(3*Pi*t) or something like that.

I hope this helps,

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