A thermobaric weapon, which includes the type known as a "fuel-air bomb", is an explosive weapon that produces a blast wave of a significantly longer duration than those produced by condensed explosives. This is useful in military applications where its longer duration increases the numbers of casualties and causes more damage to structures.
Thermobaric explosives rely on oxygen from the surrounding air, whereas most conventional explosives consist of a fuel-oxygen premix (for instance, gunpowder contains 15% fuel and 75% oxidizer). Thus, on a weight-for-weight basis they are significantly more powerful than normal condensed explosives. Their reliance on atmospheric oxygen makes them unsuitable for use underwater or in adverse weather, but they have significant advantages when deployed inside confined environments such as tunnels, caves, and bunker.
In contrast to condensed explosive where oxidation in a confined region produces a blast front from essentially a point source, here a flame front accelerates to a large volume producing pressure fronts both within the mixture of fuel and oxidant and then in the surrounding air.
Thermobaric explosives apply the principles underlying the accidental unconfined vapor cloud explosions, UVCE, that includes those of dispersions of flammable dusts and droplets. One form of such explosion is boiling liquid expanding vapor explosion, BLEVE, associated with containers partly filled by pressurised liquefied gases. In previous times they were most often encountered in flour mills and their storage containers, and later in coal mines, but now most commonly in discharged oil tankers and refineries, the most recent being at Buncefield in the UK where the blast wave wakened people 150 km from its centre.
A typical weapon consists of a container packed with a fuel substance, in the center of which is a small conventional-explosive "scatter charge". Fuels are chosen on the basis of the exothermicity of their oxidation, ranging from powdered metals such as aluminium or magnesium, or organic materials, possibly with a self-contained partial oxidant. The most recent development involves the use of nanofuels.
A thermobaric bomb's effective yield requires the most appropriate combination of a number of factors; amongst these are how well the fuel is dispersed, how rapidly it mixes with the surrounding atmosphere and the initiation of the igniter and its position relative to the container of fuel. In some cases separate charges are used to disperse and ignite the fuel. In other designs stronger cases allow the fuel to be contained long enough for the fuel to heat to well above its auto-ignition temperature, so that, even its cooling during expansion from the container, results in rapid ignition once the mixture is within conventional flammability limits.
It is important to note that conventional upper and lower limits of flammability apply to such weapons. Close in, blast from the dispersal charge, compressing and heating the surrounding atmosphere, will have some influence on the lower limit. The upper limit has been demonstrated strongly to influence the ignition of fogs above pools of oil. This weakness may be eliminated by designs where the fuel is preheated well above its ignition temperature, so that its cooling during its dispersion still results in a minimal ignition delay on mixing.
In confinement, a series of reflective shock waves are generated, which maintain the fireball and can extend its duration to between 10 and 50 msec as exothermic recombination reactions occur. Further damage can result as the gases cool and pressure drops sharply, leading to a partial vacuum, powerful enough to cause physical damage to people and structures. This effect has given rise to the misnomer "vacuum bomb". Piston-type afterburning is also believed to occur in such structures, as flame-fronts accelerate through it.
The overpressure within the detonation can reach 430 lbf/in² (3 MPa, 30 bar) and the temperature can be 4,500 to 5,400 °F (2,500 to 3,000 °C). Outside the cloud the blast wave travels at over 2 mi/s (3 km/s).
Father of all bombs
Aviation Thermobaric Bomb of Increased Power (ATBIP) (Russian: Авиационная вакуумная бомба повышенной мощности (АВБПМ)), nicknamed "Father of All Bombs" (FOAB) (Отец всех бомб), is a Russian-made air-delivered/land activated thermobaric weapon. In describing the bomb's destructive power, Russian deputy armed forces chief of staff Alexander Rukshin was quoted as saying, "all that is alive merely evaporates." The bomb is reportedly four times as powerful as the U.S. military's GBU-43/B Massive Ordnance Air Blast bomb (official military acronym "MOAB" is often colloquially said as the "Mother of All Bombs"). This would make it the most powerful conventional (non-nuclear) weapon in the world, although the legitimacy of the weapon's size and power has been called into question by some U.S defense analysts.
The bomb was successfully field-tested in the late evening of September 11, 2007. According to the Russian military, the new weapon will replace several smaller types of nuclear bombs in its arsenal.
The vacuum device yields the equivalent of 44 tons of TNT using 7.8 tons of a new type of high explosive developed with the use of nanotechnology. Because of this, the bomb has the same destructive power as a small tactical nuclear weapon. The bomb works by detonating in mid-air. Most damage is inflicted by a supersonic shockwave and extremely high temperatures, which incinerates everything nearby. Thermobaric weapons differ from conventional explosive weapons by using oxygen from the atmosphere, rather than carrying an oxidizing agent in their explosives. They produce more energy than normal weapons but are harder to control.
According to General Alexander Rushkin, the Russian deputy chief of staff, the new bomb is smaller than the MOAB but much deadlier because, due to nanotechnology, the temperature at the centre of the blast is twice as high. He says the bomb's capabilities are comparable to nuclear weapons, but unlike a nuclear weapon, use of the weapon does not damage or pollute the environment beyond the blast radius.
In comparison, the MOAB produces the equivalent of 11 tons of TNT from 8 tons of high explosive. The blast radius of the FOAB is 300 m, more than double that of the MOAB, and the temperature produced is
twice as high.
Comparison with MOAB
Indicator MОАВ FОАВ
Mass: 8,200 kg 7,100 kg
TNT equivalent: 11 tons / 20,000 Ib 44 tons / 80,000 Ib
Blast radius: 150 m (500 ft) 300 m (1,000 ft)
Guidance: INS/GPS Unknown
by Kevin Hand A computerized fuse clocks the decreasing altitude of the bomb and ignites at a predetermined height, setting off a chain of blasts Kevin Hand
Type Thermobaric vacuum bomb
Place of origin Russia
Used by Russian Air Force
Designer Russian Military
Weight 7,100 kg (7.1 tonnes)
Filling High explosive and fine Aluminium powder and Ethylene oxide mix.
Blast yield 44 tons TNT / 80,000 Ibs
Fuel-air weapons work by releasing and igniting a blooming cloud of explosive material. Unlike conventional bombs, the weapons generate sustained shock waves that can propagate outward up to 990 feet, inflicting damage far beyond the central area of impact. The footage showed a giant explosion that flattened a building within seconds. (Check out the video below.)
Explosives engineer Jerome Stofleth of Sandia National Laboratories calls the fuel-air bomb a specialty weapon, excellent at collapsing tunnels and bunkers because its shock waves can easily penetrate small spaces. But fuel-air weapons have a few serious drawbacks that limit their potential usefulness on the battlefield. First, they are notoriously difficult to build. "It's more of an art than a science to get the right concentration of fuel and air," says Van Romero, a weapons expert at New Mexico Tech. What's more, wind can blow away the fuel cloud before it ignites, leaving the target unharmed. And explosives inside the weapon, often magnesium and isopropyl nitrate, can be unstable, giving the bomb an impossibly short shelf life (in some cases, days compared with decades for a TNT bomb).
So while Russia touts the size of its new weapon, military experts are more concerned over whether the Russians have managed to make it reliable. Their formulation is unknown, but "if they have figured out a way to perfect it and can repeat it when they want," Romero notes, "it could be a devastating weapon."
1. An aircraft carrying a fuel-air bomb in its weapons bay flies over its target.
2. The crew releases a bomb out of the cargo hold. It descends under a parachute.
3. A computerized fuse clocks the decreasing altitude of the bomb and ignites at a predetermined
height, setting off a chain of blasts.
4. A "booster" explodes inside the warhead, igniting explosive material and expelling air-combustible
5. The blast travels outward, penetrating bunkers and leveling buildings.
6. As the blast expands, turbulent jets at the edge of the fireball mix the uncombusted fuel with
surrounding air, igniting it.
7. The burning fuel in the jets further heats the fireball and sends a huge shock wave sweeping outward
at 6,700 mph, flattening everything in its path. Those not killed by the initial blast can suffer
blindness, hearing loss and internal organ failure, among other injuries.
8. The wave leaves a vacuum in its wake that sucks up air and debris and creates a mushroom cloud.
The entire process takes just seconds.
CUTAWAY OF FOAB
DEMO THERMOBARIC BOMB.
KEMENHAN RI PERLU MEMIKIRKAN PENGEMBANGAN JENIS SENJATA INI KARENA MASIH LEGAL SEBAGAI SENJATA PENGENTAR TNI.