US Patent 9677501 Three stream, variable area fixed aperture nozzle with pneumatic actuation

An exemplary nozzle having a variable internal exhaust area for a gas turbine engine can have a plurality of flap trains extending around a periphery of the gas turbine engine. Each flap train can include a convergent flap pivotally attached to an engine body and a divergent flap pivotally attached to the engine body downstream of the convergent flap. The nozzle can further have a fluid circuit in communication with the convergent and divergent flaps and configured to pivot the convergent and divergent flaps between a radially inward position and a radially outward position.