OCR Text |
Show (28) In the non-gray gas analysis, the monochromatic absorption coefficient a(v) is obtained by the exponential wide band model and Elsasser's fixed line model. a l v) = p (A/W)exp( -v /W)tanh(2 y P e) where, P : density of non-gray gas A : integrated band intensity W : band width parameter r : line width parameter P e : equivalent broadening pressure parameter (29) (30) Usually, there are some non-gray gases of CO2 and H20 in each radiative problem which will have several bands, that is 6 bands for CO2 and 5 bands for H20. The radiative energy from particle is obtained by Eq.(23) because the gray assumption may be applied. If the non-gray gas is used for the numerical analysis, it is important to check the above coefficient with Hottel's chart as shown in Fig.6. Furthermore, the energy spectrum and intensity from non-gray gas are also important to estimate the heat transfer effect which is shown in Fig.7. There are some windows of non-gray radiation and so many differences from gray simplicity in the analysis. Then, the non-gray concept has to be introduced in each industrial research problems. Next, the radiative heat transfer in non-gray mixture of gas and particle is calculated by the case of Fig.3 and shown in Fig.B. In this case, temperature difference between gas and particle is considered to compare the difference between nonY'"gray and gray analysis. From these results, it is clear to realize that the temperature of non-gray case will be higher than that of gray case, because non-gray gas has some radiative spectrum effect. |