Reply To: Help needed – Solar calculator, Solar BC boundary conditions

[gopalakrishna.gangisetty]

Dear AG Sir,

Thank you for the help and guiding me, I managed to calculate Absorption Coefficients based on Beer- lambert law.

a_λ = [-ln(tau)/d]; where  tau = transmittance and d = thickness

a_λ for bottom and top window glasses are :

band 1 = 21.07 m^-1;

band 2 = band 3 = band 4 = 1842 m^-1

since I assume tau = 0.1 in band 1, tau = 0.0001 for band 2 to band 4.

Refractive Index I choose 1.5 for all the bands in a regular window glass.

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a_λ for bottom and top ZnS glasses are :

band 1 = band 2 = band 3 = 57.5 m^-1

 band 4 = 1842 m^-1

since I assume tau = 0.75 in band 1, band 2 and band 3; and in band 4 = 0.0001

Refractive Index I choose. Band 1 = 2.2, band 2 = 2.2, band 3 = 2.2 and band 4 = 1.5 [this is from manufacturer data sheet).

 

I would still request your help in understanding in assuming the diffuse fractions for

·         top side window glass, Top side ZnS glass from band 1 to band 4 -----> exposed to solar

·         bottom side window glass , bottom side ZnS glass from band 1 to band 4. -----> not exposed to solar. 

Can you please enlighten me in setting diffuse fraction values in band 1 to band 4?

Thank you Sir.