radiation heat transfer

GeHa · March 22, 2012, 09:09

Hi,

I have defined a simple plane model made of a transparent solid material (Energy/DO-model). At one side, a Wall boundary condition with mixed thermal conditions is assigned. The radiation BC type is "opaque". According to the given boundary condition, I have computed the Total Heat Transfer q and the Radiation Heat Transfer (RHT) q_str. A comparison with the values obtained with "Reports>Fluxes> ... Heat Transfer Rate" shows a good agreement regarding the Total Heat Transfer Rate. But the Fluent-result for q_str is about 15 % larger than the value given by "A eps sig (T_infinity^4-T_w^4)" (A is the area of the side with the Wall boundary condition). So my question is:

How does Fluent the Radiative Heat Transfer Rate compute?

Another question: Is there a possibility to get the Radiation Heat Transfer Rate for a specific surface and for a given Wavelength Interval (in a Non-Gray Model)?

Thanks and best regards.

nenazarian · September 5, 2012, 15:56

Hi

I have a same problem as you.

Have you figure out how does Fluent compute the Radiative Heat Transfer?

Cheers
Negin

March 22, 2012, 09:09	radiation heat transfer	#1
GeHa New Member Georg Join Date: Feb 2012 Posts: 1 Rep Power: 0	Hi, I have defined a simple plane model made of a transparent solid material (Energy/DO-model). At one side, a Wall boundary condition with mixed thermal conditions is assigned. The radiation BC type is "opaque". According to the given boundary condition, I have computed the Total Heat Transfer q and the Radiation Heat Transfer (RHT) q_str. A comparison with the values obtained with "Reports>Fluxes> ... Heat Transfer Rate" shows a good agreement regarding the Total Heat Transfer Rate. But the Fluent-result for q_str is about 15 % larger than the value given by "A eps sig (T_infinity^4-T_w^4)" (A is the area of the side with the Wall boundary condition). So my question is: How does Fluent the Radiative Heat Transfer Rate compute? Another question: Is there a possibility to get the Radiation Heat Transfer Rate for a specific surface and for a given Wavelength Interval (in a Non-Gray Model)? Thanks and best regards.

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September 5, 2012, 15:56		#2
nenazarian Member Negin Nazarian Join Date: Jan 2012 Location: San Diego Posts: 61 Rep Power: 14	Hi I have a same problem as you. Have you figure out how does Fluent compute the Radiative Heat Transfer? Cheers Negin