Hello,
I work on a molten charge and i have some issues with radiation. Usually i use a surface to ambient radiation condition but it is not enough precise for my problem, i have to take into account the reflection of the surfaces (emissivity of other surfaces emi(ext)=0.1) arround my charge.
I have a quite simple geometry and the ambiant view factor is close to 0.
Problem is that i can't add gaz and other surfaces in my model.
Can i introduce a simple heat flux on a boundary representing the reflection of my surface?
I have done lot of tests with simpler geometry but i can't find a way to put the good condition wich is closed to what i can measure with surface-to-surface condition
For example:
Radiation to ambiant condition is assumed to be:
q1=emi(ch)*sigma_const*(T_cr^4-T^4) (W/m^2)
T_cr is the temperature of the surface of other elements which i don't wan't to draw, T is the surface temperature of the charge.
The reflection is:
q2=-(1-emi(ext))*emi*(ch)*sigma_const*(T_cr^4-T^4)*(1-Famb) (W/m^2)
I have already measure Famb, is closed to 0. But when i add this heat flux, solver doesn't converge. It seems that i can't bring power to my surface. I have also tried boundary heat source without success.
I am in 2d-axy
Any ideas?
I need some help
Thank you very much
I work on a molten charge and i have some issues with radiation. Usually i use a surface to ambient radiation condition but it is not enough precise for my problem, i have to take into account the reflection of the surfaces (emissivity of other surfaces emi(ext)=0.1) arround my charge.
I have a quite simple geometry and the ambiant view factor is close to 0.
Problem is that i can't add gaz and other surfaces in my model.
Can i introduce a simple heat flux on a boundary representing the reflection of my surface?
I have done lot of tests with simpler geometry but i can't find a way to put the good condition wich is closed to what i can measure with surface-to-surface condition
For example:
Radiation to ambiant condition is assumed to be:
q1=emi(ch)*sigma_const*(T_cr^4-T^4) (W/m^2)
T_cr is the temperature of the surface of other elements which i don't wan't to draw, T is the surface temperature of the charge.
The reflection is:
q2=-(1-emi(ext))*emi*(ch)*sigma_const*(T_cr^4-T^4)*(1-Famb) (W/m^2)
I have already measure Famb, is closed to 0. But when i add this heat flux, solver doesn't converge. It seems that i can't bring power to my surface. I have also tried boundary heat source without success.
I am in 2d-axy
Any ideas?
I need some help
Thank you very much