Calculation of EOT in physical trough model

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joey.hu
Topic Author

19 Dec 2013 05:13 #2046 by joey.hu

Calculation of EOT in physical trough model was created by joey.hu

Hello Paul,

When i tried to calculate the EOT(equation of time) according to your technical manual of physical trough model, i found some difference between your formula and the formula from other papers, your formula is:
EOT_sam = 9.2*(0.000075+0.001868*COS(B)-0.032077*SIN(B)-0.014615*COS(2*B)-0.04089*SIN(2*B))

while the other is :

EOT_else = 229.18*(0.000075+0.001868*COS(B)-0.032077*SIN(B)-0.014615*COS(2*B)-0.04089*SIN(2*B))

and the B is the same formula, i want to know why? and which one is the correct one?

Thanks and best regards
Joey

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Paul Gilman

19 Dec 2013 17:10 #2047 by Paul Gilman

Replied by Paul Gilman on topic Calculation of EOT in physical trough model

Hi Joey,

You can see the actual equation in the physical trough model's source code, sam_mw_trough_Type250.f90, which you can find in your SAM installation folder (c:\SAM\2013.9.20\exelib\trnsys\source by default). The equation is on Line 809:

EOT = 229.2 * (0.000075 + 0.001868 * COS(B) - 0.032077 * SIN(B) - 0.014615 * COS(B*2.0) - 0.04089 * SIN(B*2.0))

That is different than Equation 2.27 in the reference manual. I suspect the error in the manual is a typo where the first two digits of 229.2 were omitted.

Best regards,
Paul.

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joey.hu
Topic Author

23 Dec 2013 00:29 #2048 by joey.hu

Replied by joey.hu on topic Calculation of EOT in physical trough model

Hi Paul,

Ok, i see, thank you.

Best regards
Joey

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Jack Li

28 Aug 2015 08:29 #2049 by Jack Li

Replied by Jack Li on topic Calculation of EOT in physical trough model

Hi Paul,

I can not found the physical trough model's source code, for example sam_mw_trough_Type250.f90, in SAM 2015.6.30. Are these codes containing in this version? If it is not contained, how can i found them? Thanks.

Best regards,
Jack.

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