ExplosionAn explosion is a rapid expansion of gases resulting in a rapid moving pressure or shock wave. The expansion can be mechanical or it can be the result of a rapid chemical reaction. Explosion damage is caused by the pressure or shock wave.A mechanical explosion is due to the sudden failure of a vessel containing high-pressure non-reactive gas.
Shock WaveA pressure wave moving through a gas. A shock wave in open air is followed by a strong wind; the combined shock wave and wind is called a blast wave. The pressure increase in the shock wave is so rapid that the process is almost adiabatic. (Figure Next)If the shock wave is caused by reaction, it is due to stoichiometric effects or thermal-expansion effects.
The Distinction Between Fires and ExplosionsThe major distinction is the rate of energy release. Fires release energy slowly, while explosions release energy very rapidly, typically on the order of microseconds. Fires can also result from explosions and explosions from fires. Example: the release of energy from a tire.