The use of swirling flows to control the combustion processes is actual and essential, because of the hypothesis suggesting that the swirl flows allow the enhanced mixing of the reactants in the flame reaction
zone and stabilization of the processes of fuel combustion and heat energy production.
This was due to the presence of gap without flame reaction
since the gap area was filled up by significantly rich mixture exceeding the flame stability limits.
The assumptions for this model is that the charges are considered homogeneous, pressure is uniform throughout the cylinder, volume occupied by the flame reaction
zone is negligible, burned gas is at full thermodynamic equilibrium except for the N[O.sub.x], and there is no heat transfer between burned and unburned zones.
Examples of flame reaction mechanisms are given in table 12.
It should be noted that the main source of H atoms in the preflame region is from diffusion out of the reaction zone, so that inhibition at this zone could be expected to have a similar delay-effect on the flame reaction to that suggested by the halogen inhibition model.
Presumably, it was caused by soot radiation or flame reaction of metallic detergents in the lubricant oil.
It was probably caused by calcium's own flame reaction as a metallic element.
Chemical reaction in flame reaction
zone of the fuel-air mixture is induced by temperature, meaning that as temperature increases, the premixed laminar burning velocity also increases.
Presumably, that is because the flame reaction
of Na colors the flame yellow.
In recent investigations using DNS Borghesi and Mastorakos  showed that cool flame reactions
initiated at the lean part of a single droplet resulted in an increase in the local temperature in richer regions, which led to the high temperature ignition.
However, there are specific applications, where the low- and intermediate-temperature oxidative regions become important, for example, homogeneous charge compression ignition (HCCI) internal combustion engines (ICE) [4-6], lean premixed prevaporized (LPP) combustors in gas turbines [7, 8], and liquid fuel reformers for fuel cell applications [9-11] or industrial safety [12, 13]; in these cases, cool flame reactions
largely determine the overall reactivity and have to be taken into account.