THE PHYSICAL MEANING AND CRITICAL CONDITIONS OF IGNITION AND SELF-IGNITION

The profile of the self-ignition temperature in a flat vessel with different wall temperatures is calculated and the impossibility of a limiting transition to ignition is shown. Self-ignition and ignition are different physical phenomena. Self-ignition occurs in the volume of fuel without the participation of an external heat source, since ignition occurs in a narrow layer of fuel near an incandescent surface with a large heat flow from it. The inflection point, which is the bifurcation point, occurs at the initial moment of ignition of the ignition source in a non-stationary temperature profile. The physical meaning of the critical conditions of self-ignition and ignition is a violation of the heat balance at the site of a thermal explosion. Critical conditions are bifurcation surfaces separating the zones of “life” and “death” of combustible systems. They exist in the first, but they cannot get into the second, burning out at the border.

theory and critical conditions of ignition and self-ignition, bifurcation and non-return points