[Helium]

Hi guys,
I need a clarification about the differences between these terms.
Practically, it works in this way:

1. You set a value for diffuse fraction of radiation (let's say 0.5);
2. You set absorpitivity and transmissivity (0.8 and 0.4, for example);
3. Fluent evaluates the 0.8 and 0.4 from that 50% of radiation which passed.

Is it correct?

Furthermore, diffuse fraction, absorpitivity and transmissivity refer to energy or light? If you search for any kind of glass manual (I do not think I can write other websites references), it happens that values are reported in terms of transmissivity of light and energy.

Gracias