Nullary Sources

Kevin Bullis for the MIT Technology Review:

A new kind of engine under development, called a detonation engine, could save the military hundreds of millions of dollars in fuel costs every year. The technology, which military researchers are working on together with scientists at GE and other companies, could reduce fuel consumption at power plants, in ships, and on airplanes by as much as 25 percent. The Navy alone estimates that retrofitting its ships with the technology would reduce annual fuel costs by $300 to $400 million.

…

The most highly developed form of detonation engine, which has been in the works for many years, is the pulse detonation engine, the type GE is developing. Whereas combustion occurs continuously in a conventional jet engine, pulse detonation involves setting off a series of detonations—say, 60 to 100 per minute.

The Naval Research Laboratory has another idea. It involves the use of a specially designed doughnut-like combustion chamber. One explosion is set off with a spark in one part of the chamber. As the shock wave propagates out from that explosion, the researchers keep it going by feeding in a precise mixture of fuel and air ahead of it. A handful of research groups have tested small versions of the engine that burn hydrogen. And the Navy researchers recently published a paper that shows the idea can work with hydrocarbon fuels like the ones that would be used in a ship, at least in detailed computer simulations.

I’ve never heard of a detonation engine before, but that’s pretty cool.