Aircraft

Additive could keep jet fuel from exploding in crashes

Additive could keep jet fuel f...
Regular untreated jet fuel (top) and fuel with the polymer additive (bottom)
Regular untreated jet fuel (top) and fuel with the polymer additive (bottom)
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Regular untreated jet fuel (top) and fuel with the polymer additive (bottom)
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Regular untreated jet fuel (top) and fuel with the polymer additive (bottom)

Living through an airliner crash involves more than just surviving the initial impact – many people are also killed by the flames and smoke that follow when the jet fuel ignites. Researchers at Caltech, however, are trying to minimize the chances of that second part happening. They've developed an additive that helps reduce the intensity of postimpact fuel fires.

In regular jet engines, fuel is mixed with compressed air to form a fine mist that is then ignited with an electric spark, producing forward thrust. Unfortunately, that same mist easily combusts in the event of a crash, when it escapes from the combustion chamber.

To keep that from happening, a team led by Prof. Julia Kornfield developed a polymer that can be added to jet fuel without affecting its performance or energy capacity. This polymer consists of long molecular chains known as a "megasupramolecules," which are joined end-to-end via Velcro-like chemical connectors at the end of each one.

These connectors pull apart to let the megasupramolecules separate, as the fuel/polymer mix is expelled from a fuel injection nozzle. This lets the fuel work as it normally does, temporarily forming into droplets that make up a mist. If that mist isn't ignited immediately, however, the connectors reconnect with one another as the droplets meet, causing the mist to coalesce back into a less flammable concentration.

Kornfield's colleague Ming-Hsin "Jeremy" Wei is now working on creating a reactor that could produce commercial-scale quantities of the polymer. He hopes to have it up and running in less than a year.

A paper on the research was published today in the journal Science. The flame-retardant qualities of the polymer are demonstrated in the video below.

Source: Caltech

High-speed Video of Treated and Untreated Jet Fuel (with voiceover) - J. Kornfield - 2015

4 comments
Nik
All sorts of anti-fire products have been developed for aircraft in the past, but profit reigns supreme, so they were never used. I think, sadly, the same is the likely for this product, unless legislation can be make its use compulsory.
McDesign
Jet fuel can't melt steel beams . . .
Martin Hone
In all the crash film I have seen, it is the spraying of the fuel from the fuel tanks from impact being ignited from any number of ignition sources that catch fire/explode, not the injector spray in the engines.....
guzmanchinky
It's a question of cost.