Sound Velocities Through Explosives

Sound Velocity Through Explosive. Longitudinal and transverse shear sound velocities were... 

The combustion rate through the explosive is considerably lower than the detonation velocity and is always lower than the sound velocity through the given explosive. 

The damage effects from an explosion depend highly on whether the explosion results from a detonation or a deflagration. The difference depends on whether the reaction front propagates above or below the speed of sound in the unreacted gases. For ideal gases the speed of sound or sonic velocity is a function of temperature only and has a value of 344 m/s (1129 ft/s) at 20°C. Fundamentally, the sonic velocity is the speed at which information is transmitted through a gas. 

A physical explosion, for example, a boiler explosion, a pressure vessel failure, or a BLEVE (Boiling Liquid Expanding Vapor Explosion), is not necessarily caused by a chemical reaction. Chemical explosions are characterized as detonations, deflagrations, and thermal explosions. In the case of a detonation or deflagration (e.g., explosive burning), a reaction front is present that proceeds through the material. A detonation proceeds by a shock wave with a velocity exceeding the speed of sound in the unreacted material. A... 

It appears that insofar as growth to stable detonation is concerned lead azide displays characteristics similar to those of heterogeneous secondary explosives. The delayed stress excursions evident in measured stress profiles were interpreted as reactions behind the shock front. Reactions produce pressure waves which travel through the explosive at a velocity at least equal to its velocity of sound and interact with the undecomposed explosive ahead of the reaction front, causing a nonuniform rate of growth. 

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