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Will this global error cause me any problem?

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Old   February 9, 2006, 07:03
Default Will this global error cause me any problem?
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Forrest
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Hi all,

Here is the message: There are inconsistent radiation models specified for this problem. Radiative transport between domains requires the use of identical radiation models. If required, isolate domains by using the interface boundaries `Opaque' option instead of `Conservative Interface Flux'.

This message shows up when I turn on radiation for my fluid domain without turning it on for solid domains. CHT is modelled (without radiation) in the solid domains surrounded by the fluid domain. At interface boundaries, at solid domains, only one option " conservative interface flux; while fluid domain, two options - 'opaque' and conservative interface flux, so I set an emissivity under opaque option in order to represent the 'opaque' surface of the solids (bit confused here cos I thought I should be able to set it in the solid domains).The question is: do I model the radiation coming and going at the solid surfaces? If yes, should I just ignore the global error warning for this case to continue?

Thanks a lot

Forrest

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Old   February 9, 2006, 10:06
Default Re: Will this global error cause me any problem?
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opaque
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Dear Forrest,

You are fine.. It seems CFX-Pre is off on this check..

If a material is considered/modeled as Opaque, implies that radiation is absorbed in an infinitesimal layer near the boundary. Then, the radiation boundary condition for the fluid domain does not need to know there is a solid on the other side. It could even be an external wall with no CHT region..

Good luck, Opaque
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Old   February 9, 2006, 10:33
Default Re: Will this global error cause me any problem?
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Forrest
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opaque, thank you very much for your comments on this.

The solids I was modelling have a very small finite thickness (say 1.0mm), I only subdivide it by two cells since I don't expect big temperature gradient on that direction. It's a 2D modelling, there are more cells on the other direction (32 cells). During the simulation I noticed that the T-energy imbalance is oscillating all the time. I increased the solid time scales 100 times bigger than fluid, it still does the same. The T-energy imbalance in the other participating sold domains looks ok. Any suggestions about this?

Thank you again

Regards, Forrest
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