Patent ID: 8695324

Claim:
A fan assembly comprising: first and second fan stages including first and second pluralities of first and second fan blades respectively arranged circumferentially around a longitudinal axis; an arcuate platform located on each of the second fan blades at a radially outward portion of the second fan blade, such that a portion of an annular fan inner flow path is defined in the fan assembly radially inwardly of the arcuate platform wherein the second fan blades are operable to increase the pressure of a fan flow stream flowing through the annular flow path; an outer fan system comprising an outer fan first stage having at least one outer fan first blade extending radially outward from the arcuate platform and an outer fan second stage comprising at least one outer fan second blade extending radially outward from the arcuate platform and located axially aft from the outer fan first stage; a convertible fan system operable for providing a variable fan pressure ratio while an air flow into the convertible fan system remains substantially constant; the convertible fan system including a convertible fan located aft of and operatively connected to the second fan stage; the convertible fan including a plurality of convertible fan blades arranged circumferentially around a longitudinal axis on a convertible fan hub; an annular splitter located axially forward from the convertible fan blades operable for splitting an incoming flow into an inner flow and an outer flow; each of the convertible fan blades includes a radially inner portion and a radially outer portion separated by an arcuate shroud and the inner portion is operable for pressurizing the inner flow and the outer portion is operable for pressurizing the outer flow; and a convertible fan vane system located axially forward from the convertible fan, the convertible vane system including outer vanes operable for changing an outer direction of at least a portion of the outer flow and an inner vane operable for changing an inner direction of at least a portion of the inner flow.