[renaldi]

Hi Everyone,

I am using Fluent to model radiation heat transfer inside a solar collector enclosure. The enclosure is filled with air (non participating). The surfaces include specular wall (a reflector), semi-transparent wall (cover) and spectral selective wall (so, non-gray radiation). The DO is the only model that can satisfy all these surfaces.

I stumbled across a problem in determining the right pair of angular discretization (Ntheta & Nphi) and spatial discretization (mesh size). These are related to the inherent source of errors in DO, which are ray effects and false scattering. I have read from papers that "finer" is not always "better" in this particular case.

Any suggestions on how to determine the "right" pair of angular and spatial discretization? I have an idea to do monte carlo ray tracing for my system and treat the result as the "exact" and then compare it against the Fluent results, but this seems a bit too much to attack this problem.

Comments and/or suggestions are very much appreciated.

Thank you

[Milan2013]

Originally Posted by renaldi

Hi Everyone,

I am using Fluent to model radiation heat transfer inside a solar collector enclosure. The enclosure is filled with air (non participating). The surfaces include specular wall (a reflector), semi-transparent wall (cover) and spectral selective wall (so, non-gray radiation). The DO is the only model that can satisfy all these surfaces.

I stumbled across a problem in determining the right pair of angular discretization (Ntheta & Nphi) and spatial discretization (mesh size). These are related to the inherent source of errors in DO, which are ray effects and false scattering. I have read from papers that "finer" is not always "better" in this particular case.

Any suggestions on how to determine the "right" pair of angular and spatial discretization? I have an idea to do monte carlo ray tracing for my system and treat the result as the "exact" and then compare it against the Fluent results, but this seems a bit too much to attack this problem.

Comments and/or suggestions are very much appreciated.

Thank you

How did you eventually solve this? Thanks