Thermodynamics HW Solutions 886

Thermodynamics HW Solutions 886 - Chapter 11 Fundamentals...

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Chapter 11 Fundamentals of Thermal Radiation Atmospheric and Solar Radiation 11-50C The solar constant represents the rate at which solar energy is incident on a surface normal to sun's rays at the outer edge of the atmosphere when the earth is at its mean distance from the sun. It value is . The solar constant is used to estimate the effective surface temperature of the sun from the requirement that 2 W/m 1353 = s G 4 2 1 2 ) 4 ( ) 4 ( sun s T r G L σπ π = where L is the mean distance between the sun and the earth and r is the radius of the sun. If the distance between the earth and the sun doubled, the value of drops to one-fourth since G s SUN Earth L r (4 π L 2 ) G s 4 π r 2 ( σ T sun 4 ) 4 2 2 2 4 2 2 2 ) 4 ( 16 ) 4 ( ) 2 ( 4 sun s sun s T r G L T r G L = = 4 G G s1 s2 = ⎯→ = 1 2 2 2 4 16 s s G L G L 11-51C The amount of solar radiation incident on earth will decrease by a factor of Reduction factor == = σ T T sun sun new 4 4 4 4 5762 2000 68 9 , .
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This note was uploaded on 01/24/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.

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