AudiWorld Forums: FUEL AIR EXPLOSIVES: Explanation

Fuel-air weapons work by initially detonating a scattering charge within a bomb, rocket or grenade warhead. The warhead contents, which are composed of either volatile gases, liquids or finely powdered explosives, form an aerosol cloud. This cloud is then ignited and the subsequent fireball sears the surrounding area while consuming the oxygen in this area. The lack of oxygen creates an enormous overpressure. This overpressure, or blast wave, is the primary casualty-producing force. In several dozen microseconds, the pressure at the center of the explosion can reach 30 kilograms per square centimeter (427 pounds per square inch) - normal atmospheric pressure at sea level is 14.7 pounds per square inch with a temperature between 2,500-3,000 degrees Centigrade [4,532-5,432 degrees Fahrenheit]. This is 1.5 to 2 times greater than the overpressure caused by conventional explosives. Personnel under the cloud are literally crushed to death. Outside the cloud area, the blast wave travels at some 3,000 meters per second [9843 feet per second]. The resultant vacuum pulls in loose objects to fill the void.

As a result, a fuel-air explosive can have the effect of a tactical nuclear weapon without residual radiation. Since a fuel-air mixture flows easily into any cavities, neither natural terrain features nor non-hermetically sealed field fortifications (emplacements, covered slit trenches, bunkers) protect against the effects of fuel-air explosives. If a fuel-air charge is fired inside a building or bunker, the cloud is contained and this amplifies the destruction of the load-bearing components of the structure. Fuel-air can be an effective weapon against exposed enemy personnel, combat equipment, fortified areas and individual fighting positions. It can be used to clear minefields and to clear and prepare landing zones for assault forces and helicopters. It can be used to destroy communication centers and urban strong points. It can be used to defend against anti-ship missile attacks and against surface and submarine naval attacks. Fuel-air explosions can also be used as a herbicide, destroying crops and vegetation.

http://call.army.mil/fmso/fmsopubs/issues/fuelair/fuelair.htm