aircraft firegeezer on 29 Jun 2008 01:49 pm
Big Leap In Jet Engine Design
A MAJOR IMPROVEMENT IN JET ENGINE DESIGN has generated excitement in aviation circles. Dave Demerjian of WIRED magazine starts his story:
Pratt & Whitney has spent the better part of two decades developing the geared turbofan engine that burns 12 to 15 percent less fuel than other jet engines and cuts carbon dioxide emissions by 1,500 tons per plane per year. It’s being called one of the most exciting developments commercial aviation has seen in years…
“It’s technology like that geared turbofan that’s going to drive fuel efficiency forward for this industry in the short and medium term,” says Earnest Arvi of the Arvi Group. “Alternative fuels show great potential, but they’re decades away.”
What makes this fan jet different from the others is the geared turbine. Current jet engines have fans that suck air into the combustion chamber, where it is compressed, mixed with fuel, and ignited. Then it’s blown through a turbine, generating thrust. It works, but it’s inefficient because the fan is connected to the engine and turns at the same speed as the turbine. Fans work best at low speed, while turbines work best at high speed.
Pratt & Whitney solved that problem with a gearbox that lets the fan and turbine spin independently. The fan is larger and it spins at one-third the speed of the turbine, creating a quieter, more powerful engine the company says requires less fuel, emits less C02 and costs 30 percent less to maintain.
The new engine is expected to be in production by 2013.
Pratt & Whitney photo
For the full details, read the complete article HERE and you also learn some other interesting tidbits such as: If every commercial flight in the U. S. could shave 1 minute off its flight time, there would be a savings of 1.9 million tons of fuel annually.
