September 14, 2010
From an article ("Powering up") in the anti-Zionist newspaper, The Economist:
"Jet engines: A nifty new engine design promises to improve combustion efficiency, thus cutting fuel consumption and reducing emissions
IN A world worried about global warming, improving the cleanliness and efficiency of jet engines is a priority for airlines and aircraft manufacturers. It is not just altruism: greener engines also use less fuel, and so cut costs. Incremental improvements over the years have made a difference. Modern jets burn only half as much fuel per unit of thrust as their 1960s counterparts. But some people think it is time for a radical redesign. One of those people is David Lior, the boss of a small Israeli firm called R-Jet Engineering.
Jet engines rely on Isaac Newton’s third law of motion: for every action there is an equal and opposite reaction. When a jet is running, a compressor at the front draws in air and compresses it (see illustration). This air is guided and diffused by static blades to allow for easier ignition when it is mixed with fuel and ignited in a combustion chamber. The reaction comes in the form of rapidly expanding hot gases, which blast out of the rear of the jet and thus drive the aircraft forward. As they do so, they pass through another set of static blades which direct and accelerate the hot gases to turn a turbine. The turbine is connected by a shaft to the compressor at the front, thus turning it and keeping the whole process running.
The approach taken by R-Jet involves having the air and hot gases in the combustor rotate with the compressor and turbine. To achieve this, the company uses what it calls an orbiting combustion nozzle (OCN), which turns with the compressor to inject the air into the combustion chamber as a vortex. The vortex is maintained by blades that rotate on the inner casing of the combustor. This swirling action helps mix the air and fuel for a more complete and much quicker combustion. The hot gases then exit, also in a vortex, to drive the turbine."
For the rest of the article, follow the link: