radiation from surrounding

[javidss]

Hi
I have to use radiation to warm up the outside of the part. the analysis is only thermal and not stress.
i tried Interaction and first i made a Interaction Property(because the surface emissivity is temperature dependant)to make that property i used cavity radiation(and im not sure if that was right)then in the Creat Interaction i chose cavity radiation and i used that property, in this part and i used the open definition(im not sure about this one either, i chose open because it seemed to be the temperature of the surrounding and (i think this might be wrong)
all of this are happenig in Step 1 and (with steady state and automatic increment)
the problem is when i get the results it just shows the initial condition temp and the ambient temp i used in interaction and the whole part have same temp.
please help me(i'm not even sure that even i have to use cavity radiation and not something else!! )

thanks

 

[corus]

You use surface interaction, *sradiate, for radiation from surfaces to ambient. Remember to set the physical constants so that you define stefan boltzmann's constant. You only need cavity radiation if there's a cavity or something blocking the radiation. Also note that if your only boundary condition is radiation to ambient then the calculated temperatures everywhere will be that ambient temperature for steady state.

 

[javidss]

Thanks for your reply
I need radiation from ambient to my surface and i wanna know if there is Sth like that in Abaqus.
and yes i define stefan boltzmann's constant and even i defined absolute temperature.