Le décollage de la fusée Discovery vue depuis un avion en vidéo.
Tag - NASA
mardi 1 mars 2011
VIDEO: Fusée Discovery vue depuis un avion
Par Guillaume le mardi 1 mars 2011, 09:29 - Sciences
mercredi 20 janvier 2010
NASA Low Noise, Electric VTOL Personal Air Vehicle
Par Guillaume le mercredi 20 janvier 2010, 17:53 - Sciences
Conceptual design focusing on the ability of a redundant electric propulsion system to provide new capabilities for Vertical Takeoff and Landing aircraft. Specifically utilizing electric motor variable rpm to accomplish a low tipspeed prop-rotor (400 ft/sec tip speed at hover and 200 ft/sec at cruise) to accomplish an order of magnitude reduction in community noise for close proximity operations (30-40 db reduction). The variable rpm capability also achieves a 25% improvement in prop-rotor efficiency through operation at optimal advance ratios.