[Luis Delgado]

Hi, I'd like to know what radiation model to use when I have heat transfer between a transparent material (glass) and a black surface. The fluid between both surfaces is air. Thanks.

[michujo]

Hi. Can't you just solve it analytically by using shape factors stuff? Air is optically thin so you don't need to account for radiation absorption and re-emission.

Any expert on radiation out there?

Cheers,
Michujo.

[Luis Delgado]

Hi. There are models for black surfaces (rosseland), transparent surfaces (monte carlo); but i don't know what specific model to use for one black surface and one transparent surface. Yes, I don't need to account the air.

[Rami]

Originally Posted by Luis Delgado

Hi, I'd like to know what radiation model to use when I have heat transfer between a transparent material (glass) and a black surface. The fluid between both surfaces is air. Thanks.

Not sure I fully understand your problem.

If you have a semitransparent region (glass is almost fully transparent for low wavelengths, nearly fully opaque for high wavelenghs, with a sharp change of transmissivity at ~3.5um) neighbored by a fully transparent region (air) and having black boundaries, you need to solve the Radiative Transfer Equation (RTE) in addition to the energy equation. This may be done in various ways (ray tracing, discrete ordinates etc). For optically-thick regions, the Roseland model is a reasonable approximation.

If you are referring to a specific package, you should also check the limitations of the available models.