Ansys Employee



The solar ray tracing option has some limitations its effect is negligible if the solar ray tracing model includes only boundary zones that are adjacent to fluid zones in the ray tracing calculation. In other words, boundary zones that are attached to solid zones are ignored. 
So be careful with boundary and set the adjacent side to boundary as a fluid zone . This might be one of the reason why there is no solar load contribution to your problem and also check whether you have activated the energy equation which is coupled to solar load. 


On enabling the Solar ray tracing option the following things can be observed. The reflection of the direct solar load is explained in detail and how Fluent calculates it.
 Solar Ray Tracing only tracks a ray until it reaches the first opaque wall, after this there is no more ray tracing done and with this no “real” reflection.
In the boundary condition panels for walls absorptivity and (for semi-transparent walls) transmissivity has to be defined. 1 minus these values is the portion which is handled as reflected. The reflected solar flux will summed up and then distributed to the energy sources of all walls (with participation on solar ray tracing activated).
This is also called as internally scattered energy. The fraction of the scattered energy which is distributed to the walls can be changed by the TUI command
The default value is 1 so all reflected energy is distributed. A value of 0 means all reflected energy is just taken out of the calculation.
I hope this will help you in understanding about how the fluent uses solar load model.
Chaitanya Natraj