Combustion Phenomena of High Temperature Air Combustion - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 148

FIGURE 2.114 Schematic of the measurement method.

T 0 =T wall

T 1 T 2 T 3 T 4 T 5 T N-5 T N-4 T N-3 T N-2 T N-1 T N

S 1 =0 S 2 S 3 S 4 S 5 S 6 S N-4 S N-3 S N-2 S N-1 S N S N+1 =L

FIGURE 2.115 Discretization of the gas layer for solving Equation 2.30.

L L

=

∫ ∫

( ) =

′ () ′′ ′ () ′′

τ sL , exp − k s ds

ν

exp − ksds

ν

τ τ

ν ν

′

ν s a sg

s ′ s ′

where k s v and k a v are the spectral absorption coefficients of soot and gas, respectively.
Similarly, τ s v and τ g v are the spectral soot and gas emissivity.
As schematized in Figure 2.114 , the solution of Equation 2.30 was obtained
upon discretizing the gas layer into N homogeneous cells, over which temperature,
total pressure, and gas composition were assumed constant. The values of temper-
ature and species concentration that are required for the calculations are those
obtained from the in-flame measurements. These were taken at the same axial
distance as the total radiance measurements.
Under the following assumptions: