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Turbulent diffusion flame nitrogen concentration

Figure 8. Nitrogen concentration vs. temperature, determined from Raman data at position shown in Hi-air turbulent diffusion flame. The solid theoretical curve, corresponding to adiabatic conditions, was obtained by replotting the information in Figure 7. The theoretical point for stoichiometric combustion ( = 1) is shown on this curve as a filled-in circle. These Raman data were not corrected for optical background at the Raman spectral band position. Figure 8. Nitrogen concentration vs. temperature, determined from Raman data at position shown in Hi-air turbulent diffusion flame. The solid theoretical curve, corresponding to adiabatic conditions, was obtained by replotting the information in Figure 7. The theoretical point for stoichiometric combustion (<j> = 1) is shown on this curve as a filled-in circle. These Raman data were not corrected for optical background at the Raman spectral band position.
Figure 9. Nitrogen concentration vs. temperature, determined from Raman data at position shown in Ht-mr turbulent diffusion flame. These Raman data were corrected approximately for optical background at the Raman spectral band position. Figure 9. Nitrogen concentration vs. temperature, determined from Raman data at position shown in Ht-mr turbulent diffusion flame. These Raman data were corrected approximately for optical background at the Raman spectral band position.
Oxides of nitrogen and soot-related species are examples of chemical components present in very low concentrations in turbulent diffusion flames they are trace species. Trace species that maintain chemical equilibrium pose no special problems in that they may be handled directly by the methods of the preceding subsection. However, the trace species of interest often are far from equilibrium, as soot-related species always are and oxides of nitrogen almost always are. The fact that the concentrations of these species are low means that they affect the thermochemistry to a negligible extent and that finite-rate effects for them can therefore be analyzed more easily than those for major species. Methods of analysis have been developed in the literature [15], [27], [28], [82], [83]. Here we shall indicate how calculations of interest may be performed. [Pg.402]

Equation (42) cannot be used if NO concentrations approach their equilibrium values, since the net production rate then depends on the concentration of NO, thereby bringing bivariate probability-density functions into equation (40). Also, if reactions involving nitrogen in fuel molecules are important, then much more involved considerations of chemical kinetics are needed. Processes of soot production similarly introduce complicated chemical kinetics. However, it may be possible to characterize these complex processes in terms of a small number of rate processes, with rates dependent on concentrations of major species and temperature, in such a way that a function w (Z) can be identified for soot production. Rates of soot-particle production in turbulent diffusion flames would then readily be calculable, but in regions where soot-particle growth or burnup is important as well, it would appear that at least a bivariate probability-density function should be considered in attempting to calculate the net rate of change of soot concentration. [Pg.405]


See other pages where Turbulent diffusion flame nitrogen concentration is mentioned: [Pg.635]   
See also in sourсe #XX -- [ Pg.224 , Pg.225 , Pg.226 , Pg.227 ]




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