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Hitch8 August 3, 2010 04:04

Transparent Boundary
Dear CFX experts,

I'm modeling the radiation exchange within a cavity at high temperatures. The cavity has a opening at the top. I'm not sure how to define the boundary conditions at the opening that radiation emitted inside the cavity is lost trough this opening. Should I use the option "local temperature"?

Thank you very much in advanced!


stumpy August 3, 2010 14:03

No, local temperature would mean that the incoming radiation is based on the local fluid temperature at that boundary. You should set an External Black Body Temperature and specify the far field temperature.

Hitch8 August 4, 2010 02:33

Thank you very much Stumpy!
One more question: What would be the best way to model a transparent window (emissivity = 0, reflectivity = 0.06 and transmissivity = 0.96)?


ghorrocks August 4, 2010 06:30

Is it inside the simulation or a boundary condition?

If inside the domain it should be a solid domain. If you are in V12 you may also be able to do it as a thin surface/interface. If it is a boundary then forget the window and place whatever gets through the window as the boundary.

Hitch8 August 6, 2010 09:46

It is a boundary. I defined now an external black body temperature.

Thank you very much Glenn!


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