Radiation problem
 

Hi all, I am solving a radiation problem with Discrete Ordinate Radiation model. I performed an analysis with BC Type Diffuse.

Now I am trying to solve same problem with BC Type semi-transparent. While giving run, I am getting this error

Warning: radiation is not on in both neighbor cell threads (14 and 15) of semi-transparent wall zone 94. This problem MUST be fixed before solving Error: Internal error at line 743 in file 'amgif.c'. divergence detected in AMG solver Error Object: ()

Can anybody help me ? I don't have very good knowledge of radiation.

Thanks in Advance

Rahul

Re: Radiation problem
 

In the fluid zones boundary condition you should turn on 'participates in radiation'.

Don't forget to set the parameters for your semi-transparent wall.

Hope this helps,

Laika, still orbiting

Re: Radiation problem
 

Thanks Laika, I have turn on "participates in Radiation" option even for solid also. For DO model this option will be on by default for all fluid zone. Could you please focus more on "parameters for semi-transparent wall" . I don't know much about this.

Regards, Rahul

Re: Radiation problem
 

sorry Laika, I didn't write in previous message that my model working now. Actaully turning on "participates in Radiation" for solid which are in contact with that wall. Now I am activating this option for all model and it is working. Is it correct approach ? Rahul

Re: Radiation problem
 

OK, good that your model is working.

If your solid is participating in radiation, make sure you set the correct values for your material (absorption-coefficient for example)

If you use a semi-transparent wall, you should give values for the irradiation and give some indices. I refer to the manual: there is written what they all mean and how to shoose them.

Do you have info about the radiation characteristics (emisivity etc.) of your walls?

goodluck,

Laika, still orbiting

Re: Radiation problem
 

Thanks Laika, I am using emissivity properties for walls, but I am not specifying any radiation properties to material. Default values used by fluent I am keeping. Will it affect result much ? Regards, Rahul

Dear Rahul,
I also faced this problem, would you please tell me where did you turn on the "participate in radiation"?
thank you so much.

Hi Rahul I am also using the DO model but don't have an absorption coefficient for solid material except the semitransparent solid body. even some solid body is the inside body. are we required to define the boundary for those inside the semitransparent body also? and I am not able to define the absorptivity of the opaque solid body in DO solar irradiation model