solar radiation simulation in CFD, how do i get the right amount irradiation?

Question

please help today, i dont understand 'grid orientation' and solar loading parameters like sun direction vector, i've tried all i can to have the solar load give me about 1200 w/m2 but its giving me 230. i have to submit my report already but the results are just not coming up nicely, so please help now.

Answer 1

Without seeing your derivations it's next to impossible to explain why your answer differs so much from the expected amount.