Thermobaric explosives

The airborne acoustic or shock wave generated by an explosion - Detonation, -> Fuel Air Explosives, - Thermobaric Explosives. 

A new insensitive, cast-cured PBX called -135, has been developed in order to meet the requirements of US Navy s Insensitive Munitions Advanced Development Programfor High Explosives (IMAD/HE). PBXIH-135 has enhanced internal blast performance, improved non-vulnerability and penetration survivability characteristics compared with PBXN-109. Thermobaric explosives are required to defeat hard and deeply buried structures. PBXIH-135 thermobaric explosive which not only offers effective blast and thermal effects, but is also extremely insensitive to factors responsible for accidental detonation during transit or storage, may also be used for this purpose. 

The first recorded dust explosion occurred when a bakery storeroom exploded in a small city called Turin (Italy) way back in 1785. Such an explosion is also labeled as thermobaric , a chemical reaction that produces extremely high pressure and heat very rapidly. In the early 1960s, scientists began experimenting with this concept to produce a weapon that uses the same principle, but employs volatile gases and finely powered explosives. 

Mists are dust clouds in which the particles happen to be liquid. Should that liquid be combustible, even though it is nowhere near its flash-point, explosion is possible [1] [2]. Mist explosions attract increasing study [3]. It is possible that many vapour cloud explosions have had a mist component. The editor surmises that, under appropriate circumstances, evaporation of volatile mist by the heat of a vapour (or mist) explosion might generate a larger pressure pulse than simple thermobaric effects on air. Foams are inverse mists and should show similar explosive potential. 

There are two related weapon systems in this category the thermobaric weapons and the Fuel Air Systems, also known in German as aerosol bombs (FAE, Fuel Air Explosive). Both function according to the same principle. 

For thermobaric weapons (also known as EBX = enhanced blast explosives), in addition to a conventional explosion, a flammable substance (usually Al), with little or no oxidizer (e.g. oxygen) distributed in the air detonates immediately as a result of the explosion. This post-detonative reaction ( fireball of Al with air) usually occurs within jus after the detonation of the high explosive. This causes the effect of the original explosion to be magnified which results in an even larger heat... 

As discussed above, thermobaric weapons contain monopropellants or secondary explosives and energetic particles. Boron, aluminum, silicon, titanium, magnesium, zirconium and carbon can be considered to be energetic particles. The main advantage of thermobaric systems is that they release large quantities of heat and pressure, often in amounts larger than for only secondary explosives. 

In thermobaric weapons, highly aluminized secondary explosives can be used instead of monopropellants. For example, RDX in combination with a binder and a large quantity of aluminum (fuel rich) can be used. Research is currently being undertaken to investigate energetic polymers which could possibly be metallized for possible applications. 

The following relationship gives a conservative approximation for the distance from the detonation of a thermobaric weapon, which can still experience large damage as a result of the heat and pressure-wave generated. D is the distance (in meters), C is a constant (0.15 for an assumed overpressure of 70 mbar), n is the so-called yield factor from the burning (normally 0.1) and E is the energy (in J) released on the explosion and combustion. 

As a result from the rapid oxidation of surrounding oxygen a very strong suction phase is generated which is expressed by the term vacuum bomb . EO and PO are toxic and carcinogenic which has led to the development of innocuous FAE in the last fifteen years (see also -> thermobaric explosives). 

Type of -> FAE with solid fuel, mainly using aluminium or magnesium. Because their reaction with atmospheric oxygen only produces solid oxides the blast wave is primarily generated by heat of combustion ( thermobaric ) instead of expanding explosion gases. 

Details A liquid with a characteristic smell of natural gas/ether/benzene, and an epoxide. It is used to produce polyether polyols and the polymer polypropylene oxide (polypropylene glycol) and used as a preservative, and in thermobaric weapons (also called high-impulse thermobaric weapons or fuel-air explosives). 

Table 7.9 Thermobaric explosive composed of nitromethane and aluminum flakes...

For thermobaric weapons (also known as EBX = enhanced blast explosives), in addition to a conventional explosion, a flammable substance (usually Al), with... 

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