Thermobaric Explosive (Source globalsecurity.org)
Abstract: Volumetric weapons include thermobaric and fuel-air explosives (FAE). Both thermobaric and FAE operate on similar technical principles. In the case of FAE, when a shell or projectile containing a fuel in the form of gas, liquid or dustexplodes, the fuel or dust like material is introduced into the air to form acloud. This cloud is then detonated to create a shock wave of extended duration that produces overpressure and expands in all directions. In a thermobaric weapon, the fuel consists of a monopropellant and energetic particles. The monopropellant detonates in a manner simular to TNT while the particles burn rapidly in the surrounding air later in time, resulting an intense fireball and high blast overpressure. The term "thermobaric" is derived from the effects of temperature (the Greek word "therme" means "heat") and pressure (the Greek word "baros" means "pressure") on the target.
Thermobaric munitions have been used by many nations of the world and their proliferation is an indication of how effectively these weapons can be used in urban and complex terrain. The ability of thermobaric weapons to provide massed heat and pressure effects at a single point in time cannot be reproduced by conventional weapons without massive collateral destruction. Thermobaric weapon technologies provide the commander a new choice in protecting the force, and a new offensive weapon that can be used in a mounted or dismounted mode against complex environments.
Read the full text: http://www.globalsecurity.org/military/systems/munitions/thermobaric.htm