Lightweight shrouded fan

Abstract

A gas turbine engine according to an exemplary aspect of the present disclosure includes, among other things, a fan section including a fan with a plurality of fan blades rotatable about an axis and a shroud and a speed change device in communication with the fan.

What is claimed is: 
     
         1 . A gas turbine engine comprising:
 a fan section including a fan with a plurality of fan blades rotatable about an axis and a shroud; and   a speed change device in communication with the fan.   
     
     
         2 . The gas turbine engine of  claim 1 , wherein the speed change device includes a geared architecture driven by a turbine section for rotating the fan about the axis. 
     
     
         3 . The gas turbine engine of  claim 1 , wherein the shroud is located at radially outer ends of the plurality of fan blades. 
     
     
         4 . The gas turbine engine of  claim 1 , including a low pressure turbine with at least three stages and no more than six stages. 
     
     
         5 . The gas turbine engine of  claim 1 , including a fixed area nozzle in communication with the fan section. 
     
     
         6 . The gas turbine engine of  claim 1 , including a variable area nozzle in communication with the fan section. 
     
     
         7 . The gas turbine engine of  claim 1 , including a seal between the shroud and a fan case. 
     
     
         8 . The gas turbine engine of  claim 7 , wherein the seal includes at least one knife edge. 
     
     
         9 . The gas turbine engine of  claim 7 , wherein the seal includes a honeycomb structure. 
     
     
         10 . The gas turbine engine of  claim 7 , wherein the seal includes a rubber member on a radially inner surface of the fan case. 
     
     
         11 . The gas turbine engine of  claim 1 , wherein the shroud is made of a fiber composite. 
     
     
         12 . A method of assembling a gas turbine engine comprising the steps of:
 positioning a turbine section in communication with a shaft;   positioning a speed change device in communication with the shaft; and   positioning a fan section in communication with the speed change device, the fan section includes a plurality of fan blades and a shroud.   
     
     
         13 . The method as recited in  claim 12 , wherein the speed change device includes a geared architecture. 
     
     
         14 . The method as recited in  claim 12 , wherein the shroud is located at the radially outer ends of the plurality of fan blades. 
     
     
         15 . The method as recited in  claim 13 , wherein the turbine section is a low pressure turbine. 
     
     
         16 . The method as recited in  claim 14 , wherein the turbine section includes at least three stages and no more than six stages. 
     
     
         17 . The method as recited in  claim 12 , including positioning a fixed area fan nozzle in communication with the fan section. 
     
     
         18 . A method of operating gas turbine engine comprising the steps of:
 rotating a fan section including a shroud at a first speed;   rotating a turbine section at a second speed, wherein the first speed is different from the second speed.   
     
     
         19 . The method as recited in  claim 18 , wherein a speed change device is in mechanical communication with the fan section and the turbine section. 
     
     
         20 . The method as recited in  claim 18 , wherein the turbine section is a low pressure turbine.