Determination of Reflectance Function for Aluminum and Stainless-Steel Foil Surfaces

摘要

A Kirchhoff-based relationship and a Rayleigh-Rice perturbation theory were two evaluated analytical methods used to account for the reflectance function determination in rough metallic surfaces. These methods proved to be inconclusive at predicting reflectance function in rough surfaces due to the inability to handle all the dependencies a rough reflector possesses with respect to an incoming incident energy ray (intensity, magnitude, wavelength) and surface characterization (rms roughness and slope, power spectral density). Experimental determination was shown to be the best method to attain directional properties. An experimental scatterometer based on the angular discretization of the discrete ordinates or S_N method was used and tested to measure surface reflectance. Results obtained could be easily applied to radiative heat transfer calculations, radiative property determination, and surface finish parameters in manufacturing applications.