Solar Heating Space – Solar Flux

Solar Flux
Time of Year	Appears when Planet is set to Earth.Lets you specify the time of year modeled for your simulation.DateSpecifies a date in time that you set 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 set the angle in the Solar Declination box that appears when you select this option.March Equinox, June Solstice, September Equinox, or December SolsticeUse the predefined value for the solar flux at these specified times of year.Day NumberSpecifies a day in a year that you set in the Day Number box.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 the angle in the Sun Right Ascension box that appears when you select this option.
Account for Atmospheric and Other Planet Effects	Lets you evaluate 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 Planet is set to Earth and 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 Planet Parameters
Appears when the Account for Atmospheric and Other Planet Effects check box is selected.
Compute	Appears when Planet is set to Earth.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	Appears when Planet is set to Earth.Lets you select the solar flux method to specify atmospheric and Earth parameters.Atmospheric Extinction CoefficientSpecifies a day dependent parameter to compute the attenuated direct irradiation based on the values you specified in the Apparent Solar Radiation and Atmospheric Extinction Coefficient boxes. The default values match the 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 in the Solar Flux and Turbidity Factor boxes, respectively. (Suri, Marcel, and Jaroslav Hofierka., Transactions in GIS 8.2 (2004), 175-190).
Atmospheric Extinction Coefficient	Appears when Planet is set to celestial bodies other than Earth or Solar Flux Method is set to Atmospheric Extinction Coefficient when Planet is set to Earth.Sets a day dependent parameter that is used with the Apparent Solar Radiation to compute the attenuated direct irradiation. The default value matches measurements of the direct solar irradiation on a clear day at sea level. (ASHRAE. 1995. HVAC Applications. pp. 30.1-30.5).
Overcast Conditions Method	Appears when Solar Flux Method is set to Atmospheric Extinction Coefficient.Lets you select 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).
Clearness Factor	Appears when Planet is set to a celestial body other than Earth or the Overcast Conditions Method is set to Clearness Factor when Planet is set to Earth.Sets the ration between the actual local clear day direct radiation intensity and the one calculated at sea level for the same location. The Clearness Factor adjusts the attenuated direct solar irradiation.A ratio greater than 1 reflects a high elevation, compared to sea level.A ratio less than 1 reflects a cloudy sky.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 Planet is set to celestial bodies other than Earth or Solar Flux Method is set to Atmospheric Extinction Coefficient when Planet is set to Earth.Sets a factor that adjusts the diffuse solar irradiation from the sky. For more information, see Defining a solar flux.
Ground Surface Reflectance (Albedo)	Sets 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). For more information, see Defining a solar flux.
Altitude	Sets the altitude above the ground.
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 that appear when you select this check box.
Enable Explicit Planet Model	Appears when Planet is set to celestial bodies other than Earth and the Enable Explicit Sky Model check box is selected.Lets you explicitly model the planet to calculate view factors. The thermal solver creates a set of elements to model the section of the planet seen by the satellite as a segment of sphere. You specify the mesh density in the Planet Radial Mesh Density and Planet Circumferential Mesh Density boxes.
Planet Mean Radius	Appears when Planet is set to celestial bodies other than Earth and the Enable Explicit Planet Model check box is selected.Specifies the planet mean radius.
Enable Explicit Earth Model	Appears when Planet is set to Earth and 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 Earth seen by the satellite as a segment of sphere. You set the mesh density in the Earth Radial Mesh Density and Earth Circumferential Mesh Density boxes that appear when you select this check box.
Earth Mean Radius	Appears when Planet is set to Earth and the Enable Explicit Earth Model check box is selected.Specifies the Earth's mean radius.

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