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Old   May 2, 2012, 05:14
Default heat flux vectors
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Dear all,

I need to display heat flux vectors in a domain but in variables menu there is no heat flux option.

Could it be solved by the expression? Which expression should I use? q = lambda * deltaT?

Please help.

Thanks for all answers.

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Old   May 2, 2012, 18:24
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That is because heat flux is not a vector quantity. It is a scalar.
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Old   May 3, 2012, 04:23
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Thanks for reply but if I want to display "path" of the heat going through the domain from warmer to colder position, how should I call it? because this is what I would like to see..
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Old   May 3, 2012, 07:25
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this is what I meant. It is done in Mechanical Thermal and I would like to have the same vectors in CFX.
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File Type: jpg heat flux.jpg (33.1 KB, 33 views)
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Old   May 3, 2012, 07:25
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Then you want the gradient of the temperature, enthalpy or something similar. Have a look in the "..." variables in CFD-Post and look for temperature.grad.
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Old   May 3, 2012, 07:59
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I want to have exactly the same thing which is displayed on the image above. No temperatures, no enthalpy. I know that in CFX you are able to display heat flux on the walls only, that is why it is scalar. But inside the solid domain there must be some way how to do that.
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Old   May 3, 2012, 08:46
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The gradient of temperature is proportional the heat flux.
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Old   May 4, 2012, 06:28
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thanks glenn, I displayed temperature gradient and it seems to be ok but I think that it shows vectors conversly (Vectors are in direction from colder to hotter position). Can I switch the direction somehow?

Thank you for your replies.
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Old   May 4, 2012, 06:34
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You can generate a user defined variable in CFD-Post which has the inverse of the components, U component = -temperature.grad U etc.
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Old   May 4, 2012, 07:12
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thanks a lot again, appreciate your help
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