A turbofan engine includes fan section including a plurality of fan blades, a gear train, a low spool including a low pressure turbine and a low pressure compressor, the low pressure turbine driving the plurality of fan blades through the gear train, and a high spool including a high pressure turbine driving a high pressure compressor. A fan nacelle at least partially surrounds a core nacelle to define a fan bypass flow path. A fan variable area nozzle is in communication with the fan bypass flow path and defines a fan nozzle exit area between the fan nacelle and the core nacelle. The fan variable area nozzle varies the fan nozzle exit area.

A control system operable includes a modified primary control parameter for an aircraft, the control system includes: a primary control parameter leg configured to output a demand in an aircraft primary control parameter; a primary control parameter compensation leg configured to receive a change in absolute levels and/or spatial distributions of swirl angle and/or fan pressure at a primary control parameter relative to a reference and convert the change into the primary control parameter; a processor adapted to receive the demand in the primary control parameter output from the primary control parameter leg and the change to the primary control parameter output from the primary control parameter compensation leg; compare the demand in the primary control parameter output from the primary control parameter leg and the change to the primary control parameter output from the primary control parameter compensation leg; and generate a modified primary control parameter for the aircraft.

A gas turbine engine is disclosed with a bypass flow path having a bypass nozzle positioned downstream of a fan; a core flow path having a compressor, a combustor, a turbine and an exhaust nozzle; an auxiliary duct fluidly connecting the core flow path and the bypass flow path downstream of the turbine; and a control valve operably connected to the auxiliary duct to control fluid flow from the core flow path into the bypass flow path.

A gas turbine engine is disclosed with a bypass flow path having a bypass nozzle positioned downstream of a fan; a core flow path having a compressor, a combustor, a turbine and an exhaust nozzle; an auxiliary duct fluidly connecting the core flow path and the bypass flow path downstream of the turbine; and a control valve operably connected to the auxiliary duct to control fluid flow from the core flow path into the bypass flow path.

A method of estimating a parameter of a fluid flowing in a passage includes: having a plurality of instruments operable to measure one or more fluid properties flowing in the passage, the plurality of instruments being disposed in the passage and arranged within a common measurement plane; assigning a stream tube to each instrument, each stream tube represents a region of space in the common measurement plane within the passage and each stream tube surrounds one of the plurality of instruments, the stream tubes together correspond to the cross-sectional shape and area of the passage in the common measurement plane; measuring the one or more fluid properties using the instruments to obtain one or more measured values for each stream tube; using the measured value(s) for each stream tube to calculate a derived value for each stream tube; and summing the derived values across all of the stream tubes.

A variable area nozzle assembly for a gas turbine engine includes a fixed structure surrounding an exhaust duct extending along a nozzle centerline. The fixed structure includes an upper side and a lower side opposite the upper side. The variable area nozzle assembly further includes a nozzle disposed about the nozzle centerline. The nozzle includes a nozzle throat cross-sectional area and a nozzle outlet cross-sectional area downstream of the nozzle throat cross-sectional area. The nozzle includes an upper panel and a lower panel. The upper panel includes an upper downstream end and the lower panel including a lower downstream end. The upper downstream end and the lower downstream end define a portion of the nozzle throat cross-sectional area. The variable area nozzle assembly further includes a nozzle actuation system including an upper shaft connected to the upper panel and a lower shaft connected to the lower panel.

A variable area nozzle assembly for a gas turbine engine includes a fixed structure surrounding an exhaust duct extending along a nozzle centerline. The fixed structure includes an upper side and a lower side opposite the upper side. The variable area nozzle assembly further includes a nozzle disposed about the nozzle centerline. The nozzle includes a nozzle throat cross-sectional area and a nozzle outlet cross-sectional area downstream of the nozzle throat cross-sectional area. The nozzle includes an upper panel and a lower panel. The upper panel includes an upper downstream end and the lower panel including a lower downstream end. The upper downstream end and the lower downstream end define a portion of the nozzle throat cross-sectional area. The variable area nozzle assembly further includes a nozzle actuation system including an upper shaft connected to the upper panel and a lower shaft connected to the lower panel.

A gas turbine includes a compressor, a turbine, and a combustor disposed downstream from the compressor and upstream from the turbine. The combustor includes an end cover. The combustor also includes a flange. The flange includes an internal fluid passage defined within the flange and the flange is coupled to an internal face of the end cover. A fuel port is integrally joined with the flange. The fuel port extends through the end cover between the flange and an inlet positioned outside of the end cover. The inlet of the fuel port is in fluid communication with the internal fluid passage of the flange.

A gas turbine includes a compressor, a turbine, and a combustor disposed downstream from the compressor and upstream from the turbine. The combustor includes an end cover. The combustor also includes a flange. The flange includes an internal fluid passage defined within the flange and the flange is coupled to an internal face of the end cover. A fuel port is integrally joined with the flange. The fuel port extends through the end cover between the flange and an inlet positioned outside of the end cover. The inlet of the fuel port is in fluid communication with the internal fluid passage of the flange.

A turbofan engine according to an example of the present disclosure includes, among other things, a fan section including a plurality of fan blades, a gear train, a low pressure turbine driving the fan section through the gear train, a fan nacelle and a core nacelle, the fan nacelle at least partially surrounding the core nacelle, a fan bypass flow path defined between the core nacelle and the fan nacelle, and a fan variable area nozzle in communication with the fan bypass flow path, and defining a fan nozzle exit area between the fan nacelle and the core nacelle. The fan variable area nozzle includes a first fan nacelle section and a second fan nacelle section, the second fan nacelle section movably mounted relative the first fan nacelle section and moveable axially along an engine axis of rotation relative the first fan nacelle section, defining an auxiliary port that extends between the first fan nacelle section and the second fan nacelle section.