Explosive velocity

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Explosive velocity is the velocity at which the shockwave front travels through a detonated explosive. It is usually measured in metres per second (m.s^-1), but is only ever a rough prediction based upon gas behavior theory, (see Chapman-Jouguet condition) as in practise it is rather hard to measure. Velocities often reach into several kilometres per second, as is the case for nitroglycerin, where the explosive velocity has been cited as 7700 m.s^-1.

If the explosive is confined before detonation (such as TNT in an artillery shell), the force produced is focused on a much smaller area, and the pressure is massively intensified. This results in explosive velocity that is much higher than if the explosive had been detonated in open air. Even ordinary flour can be made to explode under such conditions.

[edit] Velocity of detonation

The velocity of detonation of an explosion is the rate at which the detonation/combustion wave travels through the explosive product. The speed or how fast the chemical reaction occurs or the rate of the reaction. Velocity of explosion (VOE) refers to both high and low explosives. The reaction speed is measured in feet per second or meters per second.

Typical detonation velocities in gases range from 1800 m/s to 3000 m/s. Typical velocities in solid explosives often range beyond 6000 m/s to 8400 m/s.