propfan(redirected from Unducted fan engine)
An advanced turboprop with very thin, highly swept blades to reduce both compressibility losses and propeller noise during high-speed cruise.
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.