Flame Characteristics of Vaporized Renewable Fuels and Their Blends with Petroleum Fuels - Novel Combustion Concepts for Sustainable Energy Development - page 301

Fig. 6 Radiative fraction of
heat release of Jet A and P100
flames

than that in the Jet A fl flames, the CO concentration was higher at 25 and 50 % fl ame

heights for the PME flames, resulting in more gas radiation. The radiative fraction

of heat release in the PME

fl

fl flame was lower (almost one-half) than that of the Jet A

fl flames at the equivalence ratio of 7, because of lower soot concentration and

comparable gas concentration.

5.4 In-Flame Temperature Pro les

The in- fl ame temperature pro les (Fig. 7 a c) displayed a double-hump pro le, with

-

the peak temperature occurring about 6 - 8 mm away from the centerline at 25 %

fl flame height (FL). The maximum value shifted to the centerline by mid- fl ame

height due to entrainment and mixing. The peak temperatures at 25 % fl flame height

were comparable in the Jet A and P100 flames. As the equivalence ratio was

increased, the peak temperature was reduced due to mixing with the entrained cool
room air. The temperature at 75 %

fl

fl flame height in the PME fl flames was lower than

that of the Jet A flames at equivalence ratios of 2 and 3; the values were comparable

at the equivalence ratio of 7. The differences in the diameter of soot particles
formed in the PME and Jet A

fl

flames and the opposing effects of soot burning and
radiative loss from the soot particles could be a reason for this behavior. Previous
studies (Merchan-Merchan et al. 2012 ) have shown that the soot particles formed in
canola methyl ester

fl

fl flames were one-half the size of diesel soot and those formed in