ME 556 Solar Energy Conversion Lecture 9
Radiative Properties: Selective Surfaces & Transparent Materials
Calculating Total Emittance Assuming no direction effects f is the Black Body fraction for a particular wavelength band
Ideal Selective Surface
Program to calculate band radiation
Real Selective Surfaces Put a thin layer of good absorber on a poor emitter (thin film coating) Put very small metal particles on the surface (black chrome or black gold) Alter the surface roughness with small cavities
Real Selective Surface
Specular Reflectors
Radiation on Transparent Media
Snell’s and Fresnel’s Laws Only treats one surface
Polarization NOTE: The bars shown on the polarizer in Figure 1 are for illustration only. Actual polarizers can be made with very fine wires that resemble bars, but then they would run the other way (horizontal bars allow vertically polarized light to pass)
Reflected light is often Polarized
LCD Display