Airbus, Pratt & Whitney Begin Joint Flight Testing of Geared Turbofan Engine
15 October 2008
Airbus and Pratt & Whitney have launched joint flight testing of the PurePower PW1000G Geared Turbofan engine (earlier post) with the first on an Airbus-owned A340 test aircraft in Toulouse, France.
The PW1000G engine uses a state-of-the-art gear system allowing the engine’s fan to operate at a different speed than the low-pressure compressor and turbine. The result is a step-change improvement in fuel efficiency and a slower fan speed for much lower noise. The PurePower PW1000G engine is an all new centerline engine that includes next generation technology in every major module.
Airbus and Pratt & Whitney have partnered on flight testing a technology demonstrator of the PW1000G engine, which feature’s Pratt & Whitney’s patented Geared Turbofan technology and targets double-digit improvements in fuel burn, environmental emissions, engine noise and operating costs. The Airbus testing follows Pratt & Whitney’s own ground and flight test program.
The joint Airbus and Pratt & Whitney flight test program follows 12 flights and approximately 43 flight hours on Pratt & Whitney’s 747SP flying test bed. The A340 flight testing, which will include approximately 75 flight hours, will focus on engine performance and acoustic testing while providing valuable installation and operating data.
Airbus will be the first aircraft manufacturer to fly the PurePower PW1000G demonstrator engine on its own flight test aircraft. Test results will contribute to the company’s long-term research and technology assessment of new engine configuration developments.
It has been known for decades that the turbo prop is more efficient than the fan jet which was just a disguised half way version from the jet to the turboprop. This is just another step. The piston engine has now again become the engine of high efficiency for ships. Is it now time to start building diesel engines for large aircraft. Small aircraft are being refitted with diesel engines for longer range and cheaper operation and much cheaper fuel. Perhaps the newer stronger alloys now possible will allow high horse power diesel engines to power large aircraft at high efficiency. ..HG..
Posted by: Henry Gibson | 15 October 2008 at 07:53 AM
I don't think diesel engines for airplanes is a good idea outside of small personal planes. Because diesel engines require a stronger engine block and more noise suppression, that means a diesel engine will be heavier even with the use of modern metallurgy to build the engine block compared to a gasoline-fueled engine of the same power.
Besides, with the geared turbofan and improved combustor designs, you can now get 22-23% better fuel efficiency than today's engines anyway, which is a significant improvement by anybody's standards.
Posted by: Raymond | 15 October 2008 at 08:56 AM
Back to The Future.
Napier Nomad
Posted by: DS | 15 October 2008 at 10:57 AM
Posted by: Reality Czech | 15 October 2008 at 11:28 AM
Henry, diesel turboprops or plain piston props may be marginally better in efficiency, but the noise pollution is a show-stopper. The geared turbofan closes the gap in efficiency, and cuts noise well below other turbofans.
Already small jets have replaced small prop planes. Before long there just won't be any airport whose neighbors will allow you to take off or land the vastly louder propeller planes -- nor any passengers who will fly an airline with a significant propeller fleet.
Posted by: Adam | 15 October 2008 at 02:17 PM
External combustion engines can be much more efficient than an ICE of whatever type.
IIRC, petroleum usage in the aero segment, is only about 12% of total Transport consumption. Introducing a geared bypass fan engine that obtains a 20% improvement in efficiency, when widely adopted, would cut that 12% to under 10% of transport petroleum consumption.
Efficiency gains are progressive, and modern hi-bypass ratio jet engines, are already significantly more fuel efficient than early jets. Progress is slow, progressive, cumulative, and ... wonderful.
Although OGV large, two-cycle marine diesels are efficient, much of the reason for selection of them is due to lesser complexity and manning requirements, not thermal efficiency reasons. That and the ability to burn the dregs of the petroleum barrel, for which there is now virtually no market elsewhere, hence cheap(er) prices.
It will be interesting to see what the MARPOL T-III and T-IV and Sulfur regulations, do to the cost of marine diesel, when fully implemented in 2018.
Posted by: stas peterson | 16 October 2008 at 09:51 AM
Hi Henry,
What about your proposal for turbine expander for automobile use, eh? Going against turbine engine now?
There is no question that piston engine is for smaller aircraft and turbine engine is for larger aircraft. Small turbine engines are inefficient due to leakage around the edge of the fan disk and lower pressure ratio.
Very large turbines approach the efficient of diesel engine, due to several factors relating to size and higher number of compression stages and expansion stages. Turbine engine is much lighter and lower vibration than diesel, allowing more payload capacity from saving in structural weight and engine weight.
Posted by: Roger Pham | 16 October 2008 at 10:36 AM