A High T/W, Low Cost VTOL Propulsion System for Transformer (TX) Applications

To-date, the realization of VTOL personal air vehicles capable of executing agile missions has largely been limited by the availability of high T/W, low fuel-consumption propulsion systems with minimal noise and IR signatures. Metis Design proposes the development of an innovative, high T/W, low-TSFC turbofan in the 200-1,000 lbf thrust-class for a variety of air-vehicle applications. The proposed concept uses a novel means for coupling a high-speed turbojet core with a low-speed fan spool so as to realize a high bypass ratio turbofan (and hence, low-TSFC) in a light-weight, low-cost manner without the use of a mechanical coupling or gearbox. The critical aspects of this coupling have already been demonstrated as part of a previous DARPA-funded effort; the proposed Phase II effort therefore seeks to adapt the engine and demonstrate critical high-risk elements of the proposed technology. The Phase II effort will also demonstrate how the warm exhaust from a small turbofan engine can be used to power an all composite liftfan with a high thrust-to-weight ratio that makes it suitable for PAV application.