New-Generation GE Open Rotor and Regional Jet Engine Demo Efforts Planned

General Electric is joining with NASA to revive studies of its long-abandoned GE36 unducted fan, or "open rotor" and is simultaneously launching a next-generation CF34 technology effort as part of a pressing drive to develop families of fuel-saving engines.

GE stresses that the two-pronged move, which throws down the gauntlet to Pratt & Whitney's geared turbofan (GTF) ambitions, is part of a long-term strategy that could lead to both open-rotor and advanced conventional turbofan demonstrators in the latter part of next decade. GE and NASA have signed a Space Act agreement covering studies of the open rotor concept, which offers the potential for up to 30% lower fuel burn compared with current engines. The NG34 technology plan, aimed at regional jets, has potential for up to 20% fuel savings.

Under the cost-sharing Space Act deal with NASA, GE will refurbish all the original unducted fan (UDF) test rigs, and, with the agency, will begin a rigorous analysis of data collected during the $1.2-billion propfan program that ended almost 20 years ago. "We will then be looking at all the new technology that can be added to the system that ran back then, and at what the core would be like, the materials properties of the blades and the fan shapes," according to GE.

The thrust of the open rotor study, which is still in the stages of being refined, is to overcome noise and mechanical complexity - two major hurdles that stymied the original propfan projects.