This invention relates generally to airflow in turbofan engines, and, more specifically, to regulating the airflow through the fan duct area.
At least one known turbofan engine assembly includes a fan assembly and a core gas turbine engine enclosed in an annular core cowl. Additionally, a fan nacelle surrounds a portion of the core gas turbine engine. A nozzle assembly includes portions of the core cowl and the fan nacelle and generally defines a fan nozzle duct area (A18). While operating the turbofan engine assembly, a portion of the air flowing from the fan assembly flows through the core gas turbine engine and another portion of the air flows through the nozzle assembly.
In some turbofan engine nozzle assemblies, the fan nozzle duct area can be manipulated in order to alter engine performance. For example, some turbofan engines utilize a translating core cowl as a thrust reverser without blocker doors by essentially reducing the fan nozzle duct area.