1. The increase of the primary air greatly suppresses the concentration of soot in the annular
region of the flame. This subsequently reduces the energy transfer to the flame axis.
2. The maximum soot concentration lies inside the maximum flame temperature in both types
of flame, but the distances between these positions are larger in the double flame than those
in the diffusion flames.
3. In diffusion flame, the increase in fuel flow rate increases the amount of soot present in the
exhaust of the combustion chamber, thus increasing radiation losses. This, in turn, causes a
lower exhaust temperature.
4. In all tested diffusion flames, the rates of soot formation and maximum soot concentration
are similar at the flame axis.
5. The increase in primary air by 10% of the stoichiometric air requirement of the fuel causes
a 70% reduction in maximum soot concentration.
6. The time required to initiate soot formation at the flame axis becomes longer as the primary
air is increased.
7. In double flames, the rate of temperature increase is higher than that in diffusion flames.