Axially adjacent annular booster bleed aft and forward plenums with annular common wall therebetween extend radially outwardly from transition duct. Variable bleed valve includes bleed valve door in bleed inlet in transition duct, attached to rotatable valve body rotatable about axis of rotation, operable to open and close bleed inlet to aft plenum. Rotatable plenum door clocked or circumferentially spaced apart from variable bleed valve door and attached to rotatable valve body, operable to close and open up and control flow through an inter plenum aperture in common wall. Aft and forward bleed exhaust ducts extend from booster bleed aft and forward plenums to bypass flow path. One or more heat exchanger, such as from thermal management system, may be disposed in the bleed exhaust ducts. Heat exchangers may be used for cooling oil for power gear box and/or engine bearings, air conditioning, or variable frequency generator.

Systems and methods for adjusting airflow distortion in a gas turbine engine using a translating inlet assembly are provided. In one embodiment, a core engine of a gas turbine engine can include a compressor section, a combustion section, and a turbine section in series flow and defining at least in part an engine airflow path. The compressor section can include an inner flowpath surface. A core casing can enclose the core engine. A forward end of the core casing can include a translating inlet assembly moveable between a first position and a second position. The translating inlet assembly and the inner flowpath surface can together define an inlet to an engine airflow path. A translating inlet assembly can define a first inlet area in the first position and a second inlet area in the second position, the first inlet area being greater than the second inlet area.

An inlet apparatus for a gas turbine engine includes: a fan duct adapted to surround at least one row of rotating fan blades, the fan duct having a circular frontal area, and defining a first inlet plane; and an outer duct surrounding the fan duct, the outer duct including: a first frontal area shape at the first inlet plane which defines, cooperatively with an exterior of the fan duct, at least one lobe through which air can pass; and a second frontal area shape at a second inlet plane located axially downstream from the forward end which is circular, and which defines, cooperatively with an exterior of the fan duct, an annulus through which air can pass.

A method and system for a turbofan gas turbine engine system is provided. The gas turbine engine system includes a variable pitch fan (VPF) assembly coupled to a first rotatable shaft and a low pressure compressor LPC coupled to a second rotatable shaft. The LPC including a plurality of variable pitch stator vanes interdigitated with rows of blades of a rotor of the LPC. The gas turbine engine system also includes a speed reduction device coupled to said first rotatable shaft and said second rotatable shaft. The gas turbine engine system further includes a modulating pressure relief valve positioned between an outlet of said LPC and a bypass duct and a controller configured to schedule a position of said plurality of variable pitch stator vanes and said modulating pressure relief valve in response to an operational state of said turbofan gas turbine engine system and a temperature associated with said LPC.

A method and system for a turbofan gas turbine engine system is provided. The gas turbine engine system includes a variable pitch fan (VPF) assembly coupled to a first rotatable shaft and a low pressure compressor LPC coupled to a second rotatable shaft. The LPC including a plurality of variable pitch stator vanes interdigitated with rows of blades of a rotor of the LPC. The gas turbine engine system also includes a speed reduction device coupled to said first rotatable shaft and said second rotatable shaft. The gas turbine engine system further includes a modulating pressure relief valve positioned between an outlet of said LPC and a bypass duct and a controller configured to schedule a position of said plurality of variable pitch stator vanes and said modulating pressure relief valve in response to an operational state of said turbofan gas turbine engine system and a temperature associated with said LPC.

The invention concerns an aircraft propulsion control system in which a gas turbine engine has an actuable flow opening for control of flow to or from a portion of the engine. One or more sensor is arranged to sense a condition indicative of vapor trail formation by the exhaust flow from the engine. A controller is arranged to control actuation of the flow opening so as to reduce the efficiency of the engine upon sensing of said condition by the one or more sensor. In one example, the flow opening is a variable area fan nozzle.

A turbofan engine according to an example of the present disclosure includes, among other things, a fan including an array of fan blades rotatable about an engine axis, a compressor including a first compressor section and a second compressor section, the second compressor section including a second compressor section inlet with a compressor inlet annulus area, a fan duct including a fan duct annulus area outboard of the second compressor section inlet, and a turbine having a first turbine section driving the first compressor section, a second turbine section driving the fan through an epicyclic gearbox, the second turbine section including blades and vanes, and wherein the second turbine section defines a maximum gas path radius and the fan blades define a maximum radius, and a ratio of the maximum gas path radius to the maximum radius of the fan blades is less than 0.6.

A turbofan engine according to an example of the present disclosure includes, among other things, a fan including an array of fan blades rotatable about an engine axis, a compressor including a first compressor section and a second compressor section, the second compressor section including a second compressor section inlet with a compressor inlet annulus area, a fan duct including a fan duct annulus area outboard of the second compressor section inlet, and a turbine having a first turbine section driving the first compressor section, a second turbine section driving the fan through an epicyclic gearbox, the second turbine section including blades and vanes, and wherein the second turbine section defines a maximum gas path radius and the fan blades define a maximum radius, and a ratio of the maximum gas path radius to the maximum radius of the fan blades is less than 0.6.

An aspect includes a system for a gas turbine engine. The system includes one or more bleeds of the gas turbine engine and a control system configured to check one or more activation conditions of a dirt rejection mode in the gas turbine engine. A bleed control schedule of the gas turbine engine is adjusted to extend a time to hold the one or more bleeds of the gas turbine engine partially open at a power setting above a threshold based on the one or more activation conditions. One or more deactivation conditions of the dirt rejection mode in the gas turbine engine are checked. The dirt rejection mode is deactivated to fully close the one or more bleeds based on the one or more deactivation conditions.

An aspect includes a system for a gas turbine engine. The system includes one or more bleeds of the gas turbine engine and a control system configured to check one or more activation conditions of a dirt rejection mode in the gas turbine engine. A bleed control schedule of the gas turbine engine is adjusted to extend a time to hold the one or more bleeds of the gas turbine engine partially open at a power setting above a threshold based on the one or more activation conditions. One or more deactivation conditions of the dirt rejection mode in the gas turbine engine are checked. The dirt rejection mode is deactivated to fully close the one or more bleeds based on the one or more deactivation conditions.