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Compared with deflagration, detonation doesn't need to have an external oxidizer. Oxidizers and fuel mix when deflagration occurs. Detonation is more destructive than deflagrations. In detonation, the flame front travels through the air-fuel faster than sound; while in deflagration, the flame front travels through the air-fuel slower than sound.
As explained above, a deflagration is a subsonic reaction, whereas a detonation is a supersonic (greater than the sound speed of the material) reaction. Distinguishing between a deflagration or a detonation can be difficult to impossible to the casual observer.
Explosion of unserviceable ammunition and other military items The explosion of the Castle Bravo nuclear bomb. An explosion is a rapid expansion in volume of a given amount of matter associated with an extreme outward release of energy, usually with the generation of high temperatures and release of high-pressure gases. Explosions may also be ...
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]
Like light or sound waves, when a blast wave reaches a boundary between two materials, part of it is transmitted, part of it is absorbed, and part of it is reflected. The impedances of the two materials determine how much of each occurs. The equation for a Friedlander waveform describes the pressure of the blast wave as a function of time:
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.
Yellow smoke indicated simple explosion rather than detonation, and failure to reliably detonate was a problem with lyddite, especially in its earlier usage. To improve the detonation "exploders" with a small quantity of picric powder or even of TNT (in smaller shells, 3 pdr, 12 pdr – 4.7 inch) was loaded between the fuze and the main lyddite ...
A blast wave reflecting from a surface and forming a mach stem. The air burst is usually 100 to 1,000 m (330 to 3,280 ft) above the hypocenter to allow the shockwave of the fission or fusion driven explosion to bounce off the ground and back into itself, combining two wave fronts and creating a shockwave that is more forceful than the one resulting from a detonation at ground level.