Model of radiation
 

which model of radiation is appropriate to use when i have a combustor with two inlets (fuel and air) and a separate inlet of water that turns from water liquid to water vapor?
thank you

If I recall correctly, a high water vapor at high temperature is a participating medium and highly spectral. If the water vapor concentration is high, you may want to consider taking that into account.

For non-gray radiation (spectral radiation) use P-1 model or DO model. Rooseland has some similarities to P-1 but doesn't work in parallel. DO model is the best model that Fluent offers.

The S2S model cannot be used for participating media.

If you don't want participating media, all the models are fairly viable. DTRM, S2S, and DO models are basically ray tracing models and P-1, Rosseland solve transport equations.

Usually I used DO model for radiative problem with combustion. It is also widely employed in the industry in such situations.