BuildSysPro.BoundaryConditions.Solar.Utilities.TimeEquation

# .BuildSysPro.BoundaryConditions.Solar.Utilities.TimeEquation

Equation of time

## Information

Function computing the equation of time according to (t0 + t) given in seconds

Hypothesis and equations

The function returns the equation of time in radians according to (t0 + t) given in seconds:

ET=0.128*sin(w*(d-2)) + 0.164*sin(2*w*(d+10)

Where w=2*pi/365.25 and d day of the year according to t0+t.

The year is supposed to be not bisextile.

Bibliography

H. BOUIA, "Amélioration du temps de calcul dans BuildSysPro par traitements numériques optimisés de la conduction et des calculs solaires", Note H-E14-2013-00715-FR, 03/2013.

Instructions for use

none

Known limits / Use precautions

none

Validations

Validated function - Hassan BOUIA 03/2013.

--------------------------------------------------------------
Licensed by EDF under a 3-clause BSD-license
Copyright © EDF 2009 - 2023
BuildSysPro version 3.6.0
Author : Hassan BOUIA, EDF (2013)
--------------------------------------------------------------

#### Interface

>     function TimeEquation
>       input Real t0 = 0 "Time in seconds at t=0";
>       input Modelica.Units.SI.Time t "Time in seconds";
>       output Real ET "Equation of time (in hour)";
>     end TimeEquation;

## Revisions

Hassan Bouia 03/2013 : Simplification de l'écriture et adaptation au nouveau modèle MeteoFile

Benoît Charrier 01/2016 : Correction d'une erreur dans le calcul du quantième : remplacement de la ligne `Real d=mod((t+t0)/86400,365);` par `Real d=mod((t+t0)/86400,365)+1;`.

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