Blackbody monochromatic-emissive power

In general, the emissivity of a solid is affected by the temperature as well as the wavelength of the radiation. The concept of monochromatic emissivity is related to the radiant emission by a solid at a specific wavelength. The monochromatic emissivity e is defined as the ratio of the monochromatic-emissive power of a solid Ex to the monochromatic-emissive power of a blackbody EbX at the same temperature and wavelength, i.e.,... 

Moreover, a solid is termed a gray body if its monochromatic emissivity ex is independent of the wavelength. The monochromatic-emissive power of a blackbody at a specific temperature and wavelength is given by Planck s formula... 

Ebk Monochromatic-emissive power of blackbody radiation Po adsorbate Saturated vapor pressure... 

X Parameter, defined by Eq. (1.14) Greek Symbols Xm Wavelength at which the monochromatic-emissive power of a blackbody is maximum... 

FIG. 5-9 Spectral dependence of monochromatic blackbody hemispherical emissive power. 

The monochromatic emissivity is the ratio of the monochromatic emissive power to that of a blackbody at the same wavelength, or... 

The monochromatic emissive power of a blackbody Fs(l)(Wm 2m l) is related to temperature and wavelength by... 

This total emissive power includes all wavelengths within the thermal energy band. However, even a blackbody does not emit equally at all wavelengths. The blackbody emissive power at a particular wavelength is called the monochromatic emissive power and is related to the wavelength and temperature according to Plank s Law as... 

Heat capacity per unit mass, J kg 1-K 1 Shorthand notation for direct exchange area Area of enclosure or zone t, m2 Speed of light in vacuum, m/s Planck s first and second constants, W-m2 and m-K Particle diameter and radius, Jim Monochromatic, blackbody emissive power, W/(m2 lm)... 

Plots of vs. X from Eq. (14.6) are shown as solid lines in Fig. 14.1 for blackbody radiation at temperatures of 1000, 1500, and 2000°F. The dotted line shows the monochromatic radiating power of a gray body of emissivity 0.9 at 2000. ... 

Other past studies of several radiant sources have yielded information on the variation of radiation intensity with monochromatic wavelength ". Figure 1 illustrates the emissive powers of solar, tungsten lamp, and hexane flame radiation. The manufacturer of the tungsten lamp indicated that the emissive power of the lamps is essentially that of a blackbody at 2500 K, it provides a maximum peak at 1.15 microns 12. The spectral emissive power of the hexane flame and other hydrocarbons was measured by Ryan,... 

At this point, we consider Equation (A3.1), which is only valid for pure monochromatic incident radiation. As we are dealing with blackbody radiation, we simulate the elemental density of radiation Paidco by monochromatic radiation that has the same power. According to Equation (A3.1), the corresponding probability of elemental transition (absorption or stimulated emission) dP is as follows ... 

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