Estimate the total, hemispherical emissivity for polished

Chapter , Problem 12.44

(choose chapter or problem)

Estimate the total, hemispherical emissivity for polished stainless steel at 800 K using Equation 12.43 along with information provided in Figure 12.17. Assume that the hemispherical emissivity is equal to the normal emissivity. Perform the integration using a band calculation, by splitting the integral into five bands, each of which contains 20% of the blackbody emission at 800 K. For each band, assume the average emissivity is that associated with the median wavelength within the band m, for which half of the blackbody radiation within the band is above m (and half is below m). For example, the first band runs from 0 to 1, such that F(0l1) 0.2, and the median wavelength for the first band is chosen such that F(0lm) 0.1. Also determine the surface emissive power. 12.45 A