Convertible fan system

Abstract

A convertible fan system is disclosed having a fan rotor with a plurality of fan blades having an arcuate splitter that forms a portion of an inner flow passage and an outer flow passage wherein an inner portion of the fan blade pressurizes an inner flow in the inner flow passage and an outer portion of the fan blade pressurizes an outer flow in the outer flow passage and a vane system having an outer vane that is adapted to be able to vary the flow in the outer flow passage such that pressure ratio of the fan system can be varied.

1 . A convertible fan system comprising:
 a convertible fan rotor having a plurality of fan blades radially extending from a hub and arranged circumferentially around a longitudinal axis, each blade having an arcuate splitter located radially outward from the hub wherein the arcuate splitter forms a portion of an inner flow passage and an outer flow passage wherein an inner portion of the fan blade pressurizes an inner flow in the inner flow passage and an outer portion of the fan blade pressurizes an outer flow in the outer flow passage; and   a vane system located axially forward from the convertible fan rotor that is adapted to be able to vary the flow in inner flow passage and the outer flow passage such that pressure ratio of the fan system can be varied.   
     
     
         2 . A convertible fan system according to  claim 1  further comprising a forward fan stage coupled to the convertible fan rotor and located axially forward from it. 
     
     
         3 . A convertible fan system according to  claim 1  further comprising a splitter located axially forward from the convertible fan rotor wherein a flow stream into the convertible fan rotor is bifurcated to form the inner flow in the inner flow passage and the outer flow in the outer flow passage. 
     
     
         4 . A convertible fan system according to  claim 3  wherein the vane system comprises an outer vane located radially outward from the splitter. 
     
     
         5 . A convertible fan system according to  claim 4  wherein a portion of the outer vane is movable by an actuator. 
     
     
         6 . A convertible fan system according to  claim 3  wherein the vane system comprises an inner vane located radially inboard from the splitter. 
     
     
         7 . A convertible fan system according to  claim 6  wherein a portion of the inner vane is movable by an actuator. 
     
     
         8 . A convertible fan system according to  claim 3  further comprising an outlet guide vane located down stream from the convertible fan rotor. 
     
     
         9 . A convertible fan system according to  claim 3  wherein at least a portion of the inner flow pressurized by the inner portion of the fan blade forms a core flow. 
     
     
         10 . A convertible fan system according to  claim 3  further comprising a bypass door that is adapted to control a core bypass flow. 
     
     
         11 . A convertible fan system according to  claim 2  further comprising an outer bypass passage and an inner bypass passage. 
     
     
         12 . A convertible fan system according to  claim 11  wherein the outer bypass passage is adapted to flow at least a portion of the flow pressurized by the forward fan stage. 
     
     
         13 . A convertible fan system according to  claim 12  further comprising a blocker door that is adapted to prevent a reverse flow in the outer bypass passage. 
     
     
         14 . A convertible fan system according to  claim 11  further comprising a mixer located downstream from the convertible fan rotor that is adapted to enhance mixing of the inner bypass flow and the outer bypass flow. 
     
     
         15 . A convertible fan system according to  claim 2  wherein the forward fan stage comprises an outer fan system having a plurality of outer fan blades that are located radially outward from a plurality of fan blades and adapted to rotate with the fan blades to pressurize an outer flow stream in an outer flow path. 
     
     
         16 . A convertible fan system according to  claim 15  wherein the outer fan system further comprises a plurality of outer fan inlet guide vanes that are adapted to control the outer flow stream in the outer flow path. 
     
     
         17 . A convertible fan system comprising:
 a convertible fan rotor having a plurality of fan blades radially extending from a hub and arranged circumferentially around a longitudinal axis, each blade having an arcuate splitter located radially outward from the hub wherein the arcuate splitter forms a portion of an inner flow passage and an outer flow passage wherein an inner portion of the fan blade pressurizes an inner flow in the inner flow passage and an outer portion of the fan blade pressurizes an outer flow in the outer flow passage;   a vane system located axially forward from the convertible fan rotor comprising an outer vane located radially outward from a splitter located axially forward from the fan rotor and is adapted to be able to vary the flow in the outer flow passage such that pressure ratio of the fan system can be varied.   
     
     
         18 . A convertible fan system according to  claim 17  wherein a portion of the outer vane is movable by an actuator. 
     
     
         19 . A convertible fan system according to  claim 17  further comprising a bypass door that is adapted to control a core bypass flow. 
     
     
         20 . A convertible fan system according to  claim 17  further comprising an outer bypass passage and an inner bypass passage. 
     
     
         21 . A convertible fan system according to  claim 20  further comprising a blocker door that is adapted to prevent a reverse flow in the outer bypass passage. 
     
     
         22 . A convertible fan system according to  claim 17  further comprising a forward fan stage having an outer fan system comprising a plurality of outer fan blades that are located radially outward from a plurality of fan blades and adapted to rotate with the fan blades to pressurize an outer flow stream in an outer flow path. 
     
     
         23 . A convertible fan system according to  claim 22  wherein the outer fan system further comprises a plurality of outer fan inlet guide vanes that are adapted to control the outer flow stream in the outer flow path. 
     
     
         24 . A convertible fan system comprising:
 a convertible fan rotor having a plurality of fan blades radially extending from a hub and arranged circumferentially around a longitudinal axis, the fan blade adapted to pressurize a flow in an inner flow passage;   an inner bypass passage and an outer bypass passage located radially outward from the inner bypass passage;   a vane system located axially forward from the convertible fan rotor comprising a vane adapted to be able to vary the flow in the convertible fan rotor such that pressure ratio of the fan system can be varied.   
     
     
         25 . A convertible fan system according to  claim 24  further comprising a forward fan stage coupled to the convertible fan rotor and located axially forward from it. 
     
     
         26 . A convertible fan system according to  claim 25  wherein the forward fan stage comprises an outer fan system having a plurality of outer fan blades that are located radially outward from a plurality of fan blades and adapted to rotate with the fan blades to pressurize an outer flow stream in an outer flow path. 
     
     
         27 . A convertible fan system according to  claim 26  wherein the outer fan system further comprises a plurality of outer fan inlet guide vanes that are adapted to control the outer flow stream in the outer flow path.