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-   -   Conjugate Heat Transfer & Radiation (http://www.cfd-online.com/Forums/cfx/75964-conjugate-heat-transfer-radiation.html)

hydro May 10, 2010 17:19

Conjugate Heat Transfer & Radiation
 
I want to model radiation of a solid body in a cht-problem. So i have to use Monte Carlo Model. What i did is setting the transfer mode for the solid domain to participating media, the spectral model to gray and the material properties refractive index, absorption coefficient and scattering coefficient. In the Domain Interface Boundary Details Tab, Thermal Radiation Option is set to Opaque, Emissivity is 0.6, Diffuse Fraction is close to Zero.

As result, i get values for Radiation Intensity, but the temperature of the solid (a 900K steel plate in 300K air domain) does not change in comparison to a calculation without radiation...

What could be wrong? What steps are missing?

Thanks and regards!

ghorrocks May 10, 2010 18:57

Quote:

I want to model radiation of a solid body in a cht-problem. So i have to use Monte Carlo Model.
Incorrect. This can also be modelled using the Discrete Transfer approach. Discrete Transfer will work out view factors and is much quicker and easier than Monte Carlo. Don't use Monte Carlo unless you need the path information it provides (ie variable opacity or whatever).

The Monte Carlo model is tricky to get working properly so it does not surprise me you are having problems with it. Discrete Transfer is much easier.

hydro May 11, 2010 14:55

Yes, You are right! I accidently set up the radiation model for the solid domain instead of the fluid domain. Now, both models, the descrete transfer and monte carlo, are working and give nearly same results for the temperature field.

Thanks and regards!


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