Combustion Phenomena of High Temperature Air Combustion - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 104

100

Direct incident from high temperature
furnace wall

H O 19%
CO 9.5%
N 71.5%

2

80 Incident from nongray gas layer

2

2

60

40

20

0

0 2000 4000 6000 8000

cm -1 Wavelength, ν

FIGURE 2.74 Radiation characteristics of nongray gas and solid surfaces.

( )

sinh 2 π CD

e
D

k = ρ (2.20)

( ) − ( )

ν

cosh 2 π CD cos 2 πν * D

where ρ kg/m 3 is density of the gas, e is nondimensional line intensity, D m is line
interval, C m is half line width, and ν* = |ν - ν 0 |, where ν 0 1/m is typical wave
number of an absorption band (see Table 2.4 ) . The following equations are derived
when the notion of exponential broadband model of Edwards et al. is introduced to
Equation 2.20:

e
D

A
W

= e

ν* W

(2.21)

π C
D

= BP e (2.22)

where A is nondimensional band intensity, W is a band width parameter, B is a line
broadening parameter and P e is a pressure parameter. In cases where the cosine term
of Equation 2.23 can be neglected, then the following will be true:

A
W

( )

k = ρ e

− ν * W

tanh 2 BP (2.23)

ν e

i