Posted on 06/14/2007 9:07:50 AM PDT by Freeport
UK budget carrier EasyJet has revealed an aircraft design concept, which it claims could deliver 50% improvements to fuel efficiency and carbon dioxide emissions.
A model of the 'EasyJet EcoJet' concept aircraft, which features two rear-mounted open rotor engines integrated into the tail plane, was presented by EasyJet CEO Andrew Harrison during a press conference on the sidelines of the Low Cost Air Transport Summit in London this morning.
The budget carrier has designed the aircraft internally off the back of the latest airframer and engine manufacturer technologies, claiming that it could be ready for operation by 2015.
Harrison says: "The technology is already there to deliver the next step change. This is not Star Trek, this is within our grasp.
"This is what the next generation of aircraft will look like and we are working with the manufacturers to get this technology delivered in 2015."
EasyJet says that the concept, compared with modern aircraft like the Airbus A320 or Boeing 737, would be 25% quieter and 50% more fuel efficient, while producing 50% less carbon dioxide and 75% less NOx.
(Excerpt) Read more at flightglobal.com ...
“...and when it hits the water it will completely biodegrade in, like, two hours...”
- On climb out and approach, the airflow over the upper surface of the craft would induce turbulent flow (Nose vortices's, boundary layer, etc.) of varying magnitudes into the engines - Not good.
- The rotational effects of the forward induced prop wash (In-rushing flow filed effects) would impact the performance of the vertical & horizontal stabilizers - Not good.
That said, here is another Flight International article outlining the current research into unducted fans (UDFs.)
This was looked into back in the 70s. They test flew an engine on a DC-9. They being NASA and either GE or Pratt. Noise was a huge problem. I’d be curious how the Thrust Specific Fuel consuption (How many pounds of fuel it takes to produce a pound of thrust per hour) compares to the new very efficient “Utlra” high bypass turbo fans. I suspect at high subsonic speeds, mach .8-.9 they will leave the egg beater in the dust.
It’s all about cost per seat mile.
Warmed-over Boeing “7J7” from twenty years ago.
Repeat after me: CO2 is not a pollutant!
But I wouldn’t want to live on the runway approaches!
The only real difference I can see between this and the 7J7 is where the engines are mounted - on the 7J7 they were in roughly the same position as on the DC-9/MD8x family.
His professioin is business, not engineering. What he has is a concept based off of his preception..not necessarily reality.
If this would have saved a thenth of a penny per mile, it would have been in service 20 years ago. Even with cheap gas.
At higher angles of attack (like, on approach), wouldn’t putting the engines there tend to block airflow into them and possibly risk compressor stalls?
}:-)4
The UDF definately saves fuel, of that there is no doubt. The doubts are in getting the fan noise to meet the current very strict Stage IV noise levels around some airports, which I read is possible, and the effect the UDF has on maintenance.
Today's turbofan just keeps on chugging, where these UDFs will be more mechanically complicated because of the requirements for variable pitch blades.
But Pratt&Whitney, GE, Rolls Royce, and others are actively pursuing UDFs as an option for the next generation engine for the replacements for the A320 and B-737.
The other option being explored is the geared turbofan.
Green sky thinking - carbon credits and the propfan comeback?
"Will the emissions guys back off for the noise guys? It could be a case of 'Can you listen to the birds around the airport?' trading against the melting polar ice caps," Clapper adds.
Green sky thinking - carbon credits and the propfan comeback?
Part of the reason is the configuration changes that are required to support open rotors sized for the 25,000lb-thrust (110kN) class. Compared to the GE90-115B, currently the biggest engine in the world with a fan diameter of 3.3m (128in), the LEAP56 open rotor is provisionally outlined with a 4.3m-diameter set of blades.
"So the other piece of technology is how do you install it, and how do you certify something like that?" asks Clapper.
;^)
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