Odd results with view factor + solar load
 

Hi!

I am simulating a case with view factor radiation modeling turned on along with solar load model. The qr primary results I am getting seem reasonable but the total qr contours I am getting are very distorted and have very unreasonable values. I am attaching screenshots for reference.


The bottom face is opaque reflective with (0.03 0.07) absorptivity / emisssivity

Please help!


Thanks!

Hi,

Just my 2 cents, but I think the "distortion" you see on the qr cells is related to the face agglomeration performed before computing the view factors.

Depending on which faces are agglomerated together, and where the grouped faces are located relatively to the shadow of your object, you might get those weird values.

I hope this helps somehow.

Yann

Thanks for replying

I checked face agglomeration . Actually the distortion started to come when I divided the panel boundaries into front panel surface and rear panel surface ( My previous qr values were very low i.e. 170 W/m2 for solar radiations) . I included only rear surface and ground in view factor boundaries and then this error started to come.

Wanted to ask another thing if you know. I am getting q primary rad values of 360 W/m2 for both bands and reasonable shading as well. But the value of qr is very unrealistic. Do you know how openfoam calculates qr in view factor+solar load modeling? Assuming that qr is total radiation heat flux, then how did it become zero in areas which has q primary rad values of 360 W/m2?