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greg |
2.1 |
{ RCSid: $Id$ } |
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{ |
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glaze2.cal - double-pane fritted and low-E glazings |
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Uses BRTDfunc type to get correct behavior. |
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Oct. 2002 Greg Ward |
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We only provide support functions for the nasty expressions |
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spat out for dual-glazings by glaze.csh. |
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} |
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{ Fresnel approximation } |
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fresne = exp(-6*abs(Rdot)) - exp(-6); |
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fr(r) = r + fresne*(1 - r); |
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ft(t) = t*(1 - fresne); |
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{ glass reflectance and transmittance } |
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rclr = fr(0.076); |
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tclr = ft(0.883); |
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{ combined double-pane reflectance } |
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cr(rf,t,rb) : rf + t*t*rb; |