Solar Heating dialog box – Solar Flux

Solar Flux
Time of Year	Lets you specify the time of year modeled in your simulation.DateSpecifies a specific date in time that you specify in the Date box that appears when you select this option...Solar DeclinationSpecifies the angle between the solar vector which is the vector between the center of the celestial body and the sun, and the celestial's body equatorial plane. You specify this angle in the Solar Declination box that appears when you select this option...March EquinoxSets the date to the March equinox.June SolsticeSets the date to the June solstice.September EquinoxSets the date to the September equinox.December SolsticeSets the date to the December solstice.Day NumberSpecifies a specific day in a year that you set in the Day Number box that appears when you select this option.Sun Right AscensionSpecifies the angle that is measured eastwards from the vernal equinox vector to the projection of the sun vector on the celestial's body equatorial plane. You set this angle in the Sun Right Ascension box that appears when you select this option.
Account for Atmospheric and Other Earth Effects	Lets you include other planetary effects, such as those due to atmospheric attenuation and shadowing effects in the radiation calculation.Note: When you select this option, the total solar irradiation is the sum of the direct solar radiation, the diffuse solar irradiation from the sky, and the ground reflectivity.
Flux Value	Available when the Account for Atmospheric and Other Earth Effects check box is cleared. Sets the value for the magnitude of the solar flux. When you click Compute, the software computes the flux value depending on the time of year you specified.For more information, see Additional magnitude options.
Atmospheric and Other Earth Parameters
Appears when the Account for Atmospheric and Other Earth Effects check box is selected.
Compute	When you click Compute, the software computes values in the Apparent Solar Radiation, Atmospheric Extinction Coefficient, Diffuse Sky Radiation Factor, and Solar Flux boxes depending on the time of year you specified.
Solar Flux Method	Specifies the solar flux method to define atmospheric and Earth parameters.Atmospheric Extinction CoefficientSpecifies a day dependent parameter from the values you specified in the Apparent Solar Radiation and Atmospheric Extinction Coefficient boxes to calculate the attenuated direct irradiation. The default values matches measurements of the direct solar irradiation on a clear day at sea level. (ASHRAE. 1995. HVAC Applications. pp. 30.1-30.5).Altitude and TurbiditySpecifies the solar flux and turbidity factors that you set them in Solar Flux and Turbidity Factor boxes, respectively. (Suri, Marcel, and Jaroslav Hofierka., Transactions in GIS 8.2 (2004), 175-190.)
Overcast Conditions Method	Appears when Solar Flux Method is set to Atmospheric Extinction Coefficient.Specifies the method that defines overcast conditions to adjust the attenuated direct solar irradiation.Clearness IndexSpecifies the ratio of radiation on a horizontal surface to the extraterrestrial radiation that you set in the Clearness Index box. (Maxwell, E.L. ,1987, US)Clearness FactorSpecifies the ratio between the actual local clear day direct radiation intensity and the one calculated at sea level for the same location that you set in the Clearness Factor box. By default, this parameter is set to have no effect. (ASHRAE. 1995. HVAC Applications. pp. 30.1-30.5)
Diffuse Sky Radiation Factor	Appears when Solar Flux Method is set to Atmospheric Extinction Coefficient.Specifies a factor that adjusts the diffuse solar irradiation from the sky. See Defining a solar flux for more information.
Ground Surface Reflectance (Albedo)	Specifies the fraction of solar energy reflected from the Earth's surface back into space. Although Earth has an average albedo value of 0.3, fresh snow can have an albedo value as high as 0.87. (ASHRAE. 1995. HVAC Applications. pp 30.1–30.5) See Defining a solar flux for more information.
Altitude	Sets the altitude.
Enable Explicit Sky Model	Lets you explicitly model the sky to calculate sky view factors and shadowing effects. The thermal solver creates a set of elements, which forms a dome around the satellite, to model the sky. You set the mesh density in the Sky Radial Mesh Density and Sky Circumferential Mesh Density boxes.
Enable Explicit Earth Model	Appears when the Enable Explicit Sky Model check box is selected.Lets you explicitly model the Earth to calculate view factors. The thermal solver creates a set of elements to model the section of the Earth seen by the satellite as a segment of a sphere. You set the mesh density in the Earth Radial Mesh Density and Earth Circumferential Mesh Density boxes.
Earth Mean Radius	Appears when the Enable Explicit Earth Model check box is selected.Specifies the Earth mean radius. By default, it equals 6.371*109 mm.

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Define Solar Heating

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Solar Heating andSolar Heating Space

Defining model orientation for solar heating

Defining a solar flux

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Solar Heating dialog box – general options

Solar Heating dialog box – Model Orientation

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Solar Heating dialog box – Solar Flux, Simcenter 3D 2021.1 Series

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