[Roman1]

Good afternoon. I am modelling heat transfer between hot air and a concrete brick by chtMultyRegionFoam. Post process procedure wallHeatFlux for surrounding air (region named domain0) gives:
Domain0_to_concrete
Convective: -4846.857
Radiative: -920.5098
Total: -5767.367
, but the same procedure for region concrete gives:
Domain0_to_concrete:
Convective: -4807.125
Radiative: -0
Total: -4807.125.
Does anybody have a hint of what the reason of such a disbalance is?

[Roman1]

There was a mistake in the post, I beg your pardon.

concrete_to_domain0
Convective: -4807.125
Radiative: -0
Total: -4807.125.

[Roman1]

The differences between convective heat flux almost disappeared. There was a mistake at the radiation BC file. For the surface “domain_to_concrete” emissivity was 0.1, when the same for the surface “concrete_to_doman” was 1.

[Roman1]

Can you explain, please, whether the radiation energy from fluid region goes for the temperature increasing of the solid region. The utiluty shows that radiation leaves fluid region but does not come to the solid region.

[Roman1]

In my case radiation does leaves fluid domain but does not come to the solid domain. How can I switch on the absorbtion of the radiation on the solid region side? Thanks

[Roman1]

Thanks God and experienced users. Finally I have founded a brunch and an example needed (Adding Radiations in chtMultiRegionSimpleFoam). In my case the reason of incorrect energy transfer was wrong quality of Qr and QrNbr in BC-files for the temperature. Now the balance looks next:
Domain0_to_concrete (for fluid)
Convective: -384.1413
Radiative: -627.0502
Total: -1011.191
concrete_to_domain0 (for solid)
Convective: 1009.268
Radiative: -0
Total: 1009.268
As one can see all energy that leaves fluid region reached solid region. Small difference is not under consideration. Why radiative part is being figured as 0 I don t know at present.
Good luck