Patent ID: 9016041
Filing Date: 2015-04-28
Classification: F02K

Abstract:
1. A gas turbine engine, comprising: a front fan having at least one stage, each stage comprising a rotor carrying an annular array of fan blades disposed within a fan duct, the front fan drivingly connected to a low pressure turbine, the front fan further including at least one row of outer fan blades disposed radially outwardly of and connected to the fan blades, the row of outer fan blades radially extending across an outer bypass duct which circumscribes the fan duct; a core engine operable to produce a stream of pressurized combustion gases, the core engine axially located between the front fan and the low pressure turbine, wherein the fan blades of the front fan extend across an inner bypass duct that surrounds the core engine, and; an aft fan disposed downstream of the low pressure turbine, having at least one stage, each stage comprising a rotor carrying an annular array of aft turbine blades disposed within an aft turbine duct, the aft turbine further including at least one row of aft fan blades disposed radially outwardly of and connected to the aft turbine blades, and extending radially across an aft fan duct that surrounds the core engine and the inner bypass duct, wherein airflow of the aft fan duct and airflow of the outer bypass duct are completely physically separated from each other at all points upstream of an exit of the aft fan; and apparatus operable to selectively throttle flow through the outer bypass duct.