PROPELLERFRAMDRIVNINGSORGAN AV LEDKAPETYP MED LAG BULLERNIVA

摘要

An air propulsor having either a fixed or a variable pitch fan with blade loadings selected from a range intermediate between aircraft propeller and fan engine designs is configured so as to retain high takeoff thrust and good high-speed efficiency while providing a large reduction in noise generation. Noise is abated at its source by reducing rotative speed of the fan blades, uniquely selecting the number of stator vanes relative to the fan, and judiciously spacing the stator vanes relative to the fan and relative to each other.