Deflagration: Extremely rapid burning; distinct from detonation,
in the following significant characteristic; in deflagration, after
initial reaction begins, the chemical reaction front passes through
the substance slower than the expansive disruption generated by that
reaction – hence, significant unreacted portions of initial substance
can be isolated within and blasted free from the burning mass; conversely,
in detonation, the advancing chemical reaction front progresses through
the substance faster than the speed of sound through that substance
(in a sense it tries to outrun the shock wave that it creates but,
of course, it cannot do so because it is continuously creating a new
shock wave at the reaction front, the local compression allows the
local speed of sound to increase as necessary to allow this to happen)
– hence, very little of the mass can escape having at least begun
to react before the mass is disrupted by the ensuing shock wave (perhaps
the simplest way to view this is to represent the shock wave as coincident
with the reaction front).