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-   -   question about OpenFoam-temperatureGradient boundary condition (http://www.cfd-online.com/Forums/openfoam/86508-question-about-openfoam-temperaturegradient-boundary-condition.html)

gulru March 24, 2011 07:33

question about OpenFoam-temperatureGradient boundary condition
 
p { margin-bottom: 0.08in; } Hi all,


My problem is about applying temperature gradient to a wall in OpenFoam.


I have a rectangular box filled with gas and try to apply temperature gradient through the vertical axes. Therefore I put the fixedValue boundary condition for the up and down walls (for example 500C for up wall, 300c for down wall). But I donít know how can I determined the boundary conditions for left and right walls.
How should I define the boundary conditions to obtain temperature gradient?


It maybe so simple question but I am new in OpenFoam. Therefore, I will be appreciate for any help.


p { margin-bottom: 0.08in; } Thank you very much....

Bernhard March 24, 2011 07:48

Did you try fixedGradient?

gulru March 24, 2011 12:50

p { margin-bottom: 0.08in; } Thank you very much for your help. Actually, I thought it but I could not understand how can I use .
I read something about the fixedGradient. At one of them it is mentioned that, fixed gradient evaluate data from internalfield. If I understand it right, internalfield should not be uniform for that case. It can be define as non-uniform, but I don't have data for defining non- uniform internalfield ( for non-uniform field definition, I should have some data about temperature for each position point). Therefore I couldn't decide about fixedgradient.


If you know how can i use fixed gradient boundary condition with internalfield, could you please help me?


Moreover I am also a little bit confused about gradient value defined for fixedgradient. I am not sure that manual entry for gradient value can represent the system correctly. Actually I thought that, the program does calculates the temperature value along the wall boundaries by using hot and low temperature given for up and down wall??


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