OCR Text |
Show x = J~ Pads' ( 12) The path-averaged band strength a- = X1 J 0X adX :=: ao (13) The path-averaged band width r-o = a1x JX0 ro adX = X1 JS0 ropa tis' (14) The path-averaged line overlap -~ = ~1 JX0 ~roadX = cO1X JS0 npr opa tis' (15) ~ = y . Pe = Yo J TolT (<1>/<1>0) . Pe The optical thickness at the band center or the band head to = fiXlm (16) The total band absorptance A· = AIm = A • (a, ~, to) (17) a and A can be transformed into the mean absorption coefficient and total emissivity through the following equations. (18) (19) 2.3 Drude-Lorentz Dispersion Model [14][15][16][17][18][ 19][20] The refractive indices of soot are very important in the fields of engineering applications and numerous research, such as combustion diagnosis, thermal radiation in a combustion system, visibility of climate clouds, and carbon particle copying. Besides, if one wants to derive the surface radiation properties (absorption, radiation and reflection, ... etc.) from the electromagnetic theory, then the values of m = n - ik in the spectrum range must first be known. Therefore, it is necessary to thoroughly investigate the solution of soot materials. Classical and quantum mechanical dispersion theories have been developed to predict the phenomenological coefficients E (electrical pennittivity) and a e ( electrical conductivity) E =yl Eo =ml E' - iE" =E I Eo - iael(2rcv Eo ) = (112 - kl) - i(2nk) where E: the complex dielectric function. m: the complex index of refraction. (20) A reasonable description of optical properties of soot can be obtained by using a two bound-one free electron dispersion model as follows: (21 ) 5 |