DREAM Open Rotor Testing Underway in Europe; Results Available by Year’s End
28 July 2009
Flightglobal. The European project DREAM (valiDation of Radical Engine Architecture systeMs) began wind tunnel open-rotor blade testing in Russia earlier this month; results will be available by the end of the year.
An open rotor engine is a modified turbofan, with the fan blades placed outside the engine nacelle. Last seriously explored in the 1980s, the open rotor prototypes (such as the GE36 from General Electric) delivered a 30%+ increase in fuel efficiency. Noise, vibration, size and maintenance were issues with the open rotor concepts at the time.
| Direct-drive open rotor engine. Click to enlarge. |
DREAM is targeting the development of contra-rotating open rotors with variable pitch blades which are known to provide 10 to 15% fuel burn reduction but are noisier than high bypass turbofans. Recent progress in aero-acoustic modeling and design allow this architecture to be reconsidered for short / medium haul aircraft.
One fifth- and one seventh-scale blade testing is being carried out at Russia’s Central Aerohydrodynamic Institute on existing electrically powered rigs at speeds of up to Mach 0.85.
DREAM is a three-year €40 million (US$57 million) project led by Rolls-Royce to investigate open-rotor engines and new fuels. DREAM’s fuels work is studying synthetic kerosene produced using the Fischer-Tropsch process as well as biofuel candidates.
In the US, GE Aviation and NASA are also beginning a wind-tunnel test program to evaluate counter-rotating fan-blade systems for open rotor jet engine designs. (Earlier post.)
Resources
True high efficiency may require low speed and gear reduction turbo props. How about diesel piston engines driving props. What are you willing to give up for low CO2. ..HG..
Posted by: Henry Gibson | 28 July 2009 at 01:37 PM