Patent ID: 8943796
Filing Date: 2015-02-03
Classification: F01D,Y02T

Abstract:
1. A gas turbine engine comprising: a high spool, the high spool comprising a high pressure turbine coupled by a high pressure shaft to a high pressure compressor; an intermediate spool, the intermediate spool comprising an intermediate pressure turbine disposed axially aft of the high pressure turbine and coupled by an intermediate pressure shaft to a ducted fan disposed axially forward of the high pressure compressor; a low spool, the low spool comprising a low pressure turbine disposed axially aft of the intermediate pressure turbine and coupled by a low pressure shaft to an open-rotor propeller disposed axially forward of the ducted fan; a variable area turbine section positioned between the intermediate pressure turbine and the low pressure turbine, wherein the variable area turbine section varies an expansion ratio across the intermediate pressure turbine to control rotational speeds of the low spool and the intermediate spool; and a fan duct extending from a position just aft of the fan to an exhaust nozzle of the gas turbine engine disposed axially aft of the low pressure turbine, wherein the ducted fan generates thrust by driving bypass flow through the fan duct.