Search results
Results from the WOW.Com Content Network
Pyrotechnic deflagrations. Deflagration (Lat: de + flagrare, 'to burn down') is subsonic combustion in which a pre-mixed flame propagates through an explosive or a mixture of fuel and oxidizer. [1] [2] Deflagrations in high and low explosives or fuel–oxidizer mixtures may transition to a detonation depending upon confinement and other factors.
This is a significant distinction from deflagrations where the exothermic wave is subsonic and maximum pressures for non-metal specks of dust are approximately 7–10 times atmospheric pressure. [24] Therefore, detonation is a feature for destructive purposes while deflagration is favored for the acceleration of firearms' projectiles.
The phenomenon is exploited in pulse detonation engines, because a detonation produces a more efficient combustion of the reactants than a deflagration does, i.e. giving a higher yields. Such engines typically employ a Shchelkin spiral in the combustion chamber to facilitate the deflagration to detonation transition. [2] [3]
The detonation velocity values presented here are typically for the highest practical density which maximizes achievable detonation velocity. [ 1 ] The velocity of detonation is an important indicator for overall energy and power of detonation, and in particular for the brisance or shattering effect of an explosive which is due to the ...
It states that the detonation propagates at a velocity at which the reacting gases just reach sonic velocity (in the frame of the leading shock wave) as the reaction ceases. [ 1 ] [ 2 ] David Chapman [ 3 ] and Émile Jouguet [ 4 ] originally (c. 1900) stated the condition for an infinitesimally thin detonation.
HEVR dispersal defined as an explosion or "violent" reaction that outside of a laboratory or test-range environment can only be described as a continuum from violent deflagration to detonation (assumed 100% aerosolization).
In spark-ignition internal combustion engines, knocking (also knock, detonation, spark knock, pinging or pinking) occurs when combustion of some of the air/fuel mixture in the cylinder does not result from propagation of the flame front ignited by the spark plug, but when one or more pockets of air/fuel mixture explode outside the envelope of the normal combustion front.
Typical detonation velocities for organic dust mixtures range from 1400 to 1650 m/s. [2] Gas explosions can either deflagrate or detonate based on confinement; detonation velocities are generally around 1700 m/s [3] [4] [5] but can be as high as 3000 m/s. [6] Solid explosives often have detonation velocities ranging beyond 4000 m/s to 10300 m/s.