Hello all, i have a simple question i.e What is the difference between the incident Radiation under Radiation field variable and Surface incident radiation under wall fluxes? Also i need help on how to calculate the surface incident radiation for each band seperately. Fluent doesn't give the possibility to see these values on a band basis.

Thanks in advance

I am quite new to Fluent, so I cannot answer your last question. It is simple in principle, but I don't know if it is implemented in Fluent. Hopefully someone else will advise.

The first addresses radiative transport in general, so I will try to clarify.

Incident radiation is defined as the integral of the intensity at a point over the whole directional sphere (solid angles between 0 and 4Pi). The surface incident sphere is the same, but now only the hemisphere pointing from the surface into the domain (from which radiation is impinging on this surface) is relevant, and therefore the integral is carried on this hemisphere only.

[Junjun Guo]

Originally Posted by Rami
;155435

I am quite new to Fluent, so I cannot answer your last question. It is simple in principle, but I don't know if it is implemented in Fluent. Hopefully someone else will advise.

The first addresses radiative transport in general, so I will try to clarify.

Incident radiation is defined as the integral of the intensity at a point over the whole directional sphere (solid angles between 0 and 4Pi). The surface incident sphere is the same, but now only the hemisphere pointing from the surface into the domain (from which radiation is impinging on this surface) is relevant, and therefore the integral is carried on this hemisphere only.

There is also a value of incident radiation on the wall, but it different from the surface incident radiation. Do you know why?

[altinoluk_t]

"Incident radiation is defined as the integral of the intensity at a point over the whole directional sphere (solid angles between 0 and 4Pi). The surface incident sphere is the same, but now only the hemisphere pointing from the surface into the domain (from which radiation is impinging on this surface) is relevant, and therefore the integral is carried on this hemisphere only."

The statement I guess quite correct. Just multiply your Surface Incident Radiation value by 4 by using Expression Editor, and compare it with the Incident Radiation under Radiation. I saw these two were the same. That means, Surface incident radiation integrates the intensity over one pi, whereas Incident radiation does it for 4 pi.