propfan

(redirected from Unducted fan)

propfan

[′präp‚fan]
(aerospace engineering)
An advanced turboprop with very thin, highly swept blades to reduce both compressibility losses and propeller noise during high-speed cruise.

propfan

propfan
An advanced propeller for use at high Mach numbers. It has six to twelve blades. The sweeping of the blade delays the critical Mach number (Mcrit) and reduces the noise from the tips of the blades. The sweep also alters the phase of the noise generated by each radial section along the blade, causing a certain amount of interference. This results in noise reduction. A propfan can be used either as a pusher or a tractor.
References in periodicals archive ?
The open rotor engine, which has also been called an unducted fan and an ultra-high-bypass engine, has the axial fan mounted outside of the engine nacelle.
GE, Snecma and NASA in May plan to begin running a 1/5 scale unducted fan (UDF) rotor on a test rig at the NASA Glenn Research Center in Ohio, an experiment that is both forward looking and retrospective.
Picture: How it started back in the late 1980s, the pioneering GE36 UDF or unducted fan engine--for which its maker General Electric could claim "dramatic fuel savings"--was never launched commercially as fuel prices fell sharply at the turn of the decade.
The Old Heads are Marty Hemsworth, a pioneer of aviation's first high-bypass engine (he is providing overview critique); Joseph Al-ford, a design consultant who has contributed to the development of virtually every GE engine program over the past 50 years; Art Adamson, regarded as the father of Ge's ultramodern high-tech unducted fan engine (Tucker describes Adamson as "an innovative man who can always suggest 8 to 10 ways to solve a problem"); and Mel Bobo, the former chief engineer of GE Aircraft Engines, who retired in 1990.
CFMI is "actively pursuing counter-rotating fan technology, as well as open rotor designs that build on the experience of the unducted fan from the late 1980s" under the LEAP56 initiative.