I am trying to calculate the significance of radiation heat transfer to a fluid for a particular geometry I am modeling in Ansys. I would like to leave out radiation in the model, but I want to confirm that is it not a significant contributor first.

The problem is a gas flowing through a ceramic tube. The gas enters at room temp, and the tube is heated in the center only to over 1000 C. The result is a temperature gradient in the gas as it travels down the tube.

The best way I can think of to solve this is break the tube/gas into a few sections and give each a constant "avg" temperature for that section. Then solve each section analytically using Stefan-Boltzman, Fourier, and Newton's laws of heat transfer. Is that how you all would approach the problem? Is there a better way?


  • $\begingroup$ Evaluate for conduction, convection and radiation. $\endgroup$
    – Solar Mike
    Oct 17, 2021 at 15:37
  • $\begingroup$ What is meant when you say "heated in the center only"? A heated wire at the center heats the gas? $\endgroup$ Oct 19, 2021 at 12:45
  • $\begingroup$ Before I'd do anything complex, I would take the hottest of those sections and calculate the black body radiation wattage vs the convection wattage, and see if they are comparable, or if the former can be neglected. Even if it can't, you may be able to do the full Ansys calc without it, and just add a 20 or 30% conservative margin on your final answer. $\endgroup$
    – RC_23
    Oct 21, 2021 at 3:12


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