Turbofan engine with a core driven supercharged bypass duct

摘要

A multiple bypass turbofan engine including a core engine assembly has a fan bypass duct radially outward of the core engine assembly and has first and second inlets disposed between forward and aft fans driven by a low pressure turbine and a core engine turbine respectively. An inlet duct having an annular duct wall is disposed radially inward of the bypass duct and connects the second inlet to the bypass duct and has disposed within a supercharger means for compressing air which is drivingly connected to the core turbine. One embodiment of the aft fan may have radially inner and outer rows of aft fan vane airfoils separated by a non-rotatable portion of the annular duct wall such that the outer row of aft fan vane airfoils are disposed in the inlet duct and at least one of the aft fan vane airfoils is and, preferably, all of which are, independently variable. Radially inner and outer rows of aft fan rotor blade airfoils separated by a rotatable portion of the annular duct wall such that the outer row of aft fan rotor blade airfoils are disposed in the inlet duct adjacent to and longitudinally aft of radially inner and outer rows of aft fan vane airfoils, respectively. The radially outer rows of aft fan vane and rotor blade airfoils provide the supercharger means.