Abstract: A turbofan gas turbine engine includes a forward fan section with a row of fan rotor blades, a core engine, and a fan bypass duct downstream of the forward fan section and radially outwardly of the core engine. The forward fan section has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes downstream of the forward fan rotor blades. An exemplary embodiment of the engine includes an afterburner downstream of the fan bypass duct between the core engine and an exhaust nozzle. The variable fan outlet guide vanes are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Mach Number which may be in a range of between about 2.5-4+. Struts extend radially across a radially inwardly curved portion of a flowpath of the engine between the forward fan section and the core engine.

Abstract: A method for assembling an articulated fan front frame for a gas turbine engine facilitates improving engine performance. The method includes forming a strut including a pair of sidewalls connected at a leading edge and a trailing edge, forming a flap including a first sidewall and a second sidewall connected at a leading edge and a trailing edge, and extending in radial span between a root endwall and a tip endwall, wherein each endwall extends between the first and second sidewalls, and wherein at least one of the root endwall and the tip endwall is contoured in a radial direction extending between the flap leading and trailing edges, and pivotally coupling the flap downstream from the strut such that a gap is defined between the flap and the strut.

Abstract: A method for assembling an articulated fan front frame for a gas turbine engine facilitates improving engine performance. The method includes forming a strut including a pair of sidewalls connected at a leading edge and a trailing edge, forming a flap including a first sidewall and a second sidewall connected at a leading edge and a trailing edge, and extending in radial span between a root endwall and a tip endwall, wherein each endwall extends between the first and second sidewalls, and wherein at least one of the root endwall and the tip endwall is contoured in a radial direction extending between the flap leading and trailing edges, and pivotally coupling the flap downstream from the strut such that a gap is defined between the flap and the strut.