TURBOFAN GAS TURBINE ENGINE WITH VARIABLE FAN OUTLET GUIDE VANES

摘要

A turbofan gas turbine engine (10) includes a forward fan section (33) with a row of fan rotor blades (32), a core engine (18), and a fan bypass duct (40) downstream of the forward fan section (33) and radially outwardly of the cor e engine (18). The forward fan section (33) has only a single stage of variable fan guide vanes which are variable fan outlet guide vanes (35) downstream of the forward fan rotor blades (32). An exemplary embodiment of the engine includes an afterburner (130) downstream of the fan bypass duct (40) between the core engine (18) and an exhaust nozzle (68). The variable fan outlet guide vanes (35) are operable to pivot from a nominal OGV position at take-off to an open OGV position at a high flight Ma ch Number which may be in a range of between about 2.5 - 4+. Struts (31) extend radially across a radially inwardly curved portion (131) of a flowpath (29) of the engine (10) between the forward fan section (33) and the core engine (18).