Abstract: An aircraft assembly includes an open propulsor rotor and a turbine engine configured to drive rotation of the open propulsor rotor about an axis. The turbine engine includes a flowpath, a compressor section, a combustor section, a turbine section, an inlet vane structure and an inlet vane actuation system. The flowpath extends longitudinally through the compressor section, the combustor section and the turbine section from a flowpath inlet into the turbine engine to a flowpath exhaust from the turbine engine. The inlet vane structure is located at the flowpath inlet. The inlet vane structure includes a plurality of inlet guide vanes arranged in an annular array. Each of the inlet guide vanes extend across the flowpath. The inlet guide vanes include a first inlet guide vane. The inlet vane actuation system is configured to change at least a parameter of the first inlet guide vane.

Abstract: A bleed system for a turbine engine includes a bleed port, an inlet passage, an outlet passage, a cavity and a flow diverter. The bleed port is disposed longitudinally along a core flowpath between an inlet into the core flowpath and an exhaust from the core flowpath. The bleed port fluidly couples the core flowpath to the inlet passage. The flow diverter is configured to move between a first position and a second position. When the flow diverter is in the first position, the flow diverter fluidly decouples the inlet passage from the outlet passage, and the cavity is fluidly coupled with the inlet passage and is downstream of the flow diverter. When the flow diverter is in the second position, the flow diverter fluidly couples the inlet passage to the outlet passage.

Abstract: A bleed system for a turbine engine includes a bleed port, an inlet passage, an outlet passage, a cavity and a flow diverter. The bleed port is disposed longitudinally along a core flowpath between an inlet into the core flowpath and an exhaust from the core flowpath. The bleed port fluidly couples the core flowpath to the inlet passage. The flow diverter is configured to move between a first position and a second position. When the flow diverter is in the first position, the flow diverter fluidly decouples the inlet passage from the outlet passage, and the cavity is fluidly coupled with the inlet passage and is downstream of the flow diverter. When the flow diverter is in the second position, the flow diverter fluidly couples the inlet passage to the outlet passage.

Abstract: A fan section includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor is a four-stage low pressure compressor. The low pressure turbine is a three-stage low pressure turbine. A high spool including a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine-stage high pressure compressor. The high pressure turbine is a two-stage high pressure turbine. An exhaust gas exit temperature of greater than 900 degrees Fahrenheit and less than 1000 degrees Fahrenheit at maximum take-off.

Abstract: A fan section includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor is a four-stage low pressure compressor. The low pressure turbine is a three-stage low pressure turbine. A high spool including a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine-stage high pressure compressor. The high pressure turbine is a two-stage high pressure turbine. An exhaust gas exit temperature of greater than 900 degrees Fahrenheit and less than 1000 degrees Fahrenheit at maximum take-off.

Abstract: A fan section includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor is a four-stage low pressure compressor. The low pressure turbine is a three-stage low pressure turbine. A high spool including a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine-stage high pressure compressor. The high pressure turbine is a two-stage high pressure turbine. An exhaust gas exit temperature of greater than 900 degrees Fahrenheit and less than 1000 degrees Fahrenheit at maximum take-off.

Abstract: A gas turbine engine includes a fan section that includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor includes a greater number of stages than the low pressure turbine. A high spool includes a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine stage high pressure compressor and includes a pressure ratio per stage of greater than or equal to 1.20 and less than or equal to 1.33.

Abstract: A gas turbine engine includes a fan section that includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor includes a greater number of stages than the low pressure turbine. A high spool includes a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine stage high pressure compressor and includes a pressure ratio per stage of greater than or equal to 1.20 and less than or equal to 1.33.

Abstract: A system for controlling blade tip clearances in a gas turbine engine may comprise an active clearance control system and a controller in operable communication with the active clearance control system. The controller may be configured to identify a cruise condition, reduce a thrust limit of the gas turbine engine to a de-rated maximum climb thrust, determine a first target tip clearance based on the de-rated maximum climb thrust, and send a command signal correlating to the first target tip clearance to the active clearance control system.

Abstract: A gas turbine engine includes a fan section that includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor includes a greater number of stages than the low pressure turbine. A high spool includes a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine stage high pressure compressor and includes a pressure ratio per stage of greater than or equal to 1.20 and less than or equal to 1.33.

Abstract: A gas turbine engine includes a fan section that includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor is a five-stage low pressure compressor. The low pressure turbine is four-stage low pressure turbine. A high spool includes a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine-stage high pressure compressor. The high pressure turbine is a two-stage high pressure turbine.

Abstract: A gas turbine engine includes a fan section that includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. A high spool includes a high pressure turbine that drives a high pressure compressor. The high pressure compressor includes a pressure ratio of greater than 6.5 and less than 11.5. A ratio of a product of a pressure ratio of the fan with a pressure ratio of the low pressure compressor pressure to the pressure ratio of the high pressure compressor is greater than 0.35 and less than 0.90. An exhaust gas exit temperature is greater than 900 degrees Fahrenheit and less than 1000 degrees Fahrenheit at maximum take-off.

Abstract: A fan section includes a fan with fan blades. The fan section drives air along a bypass flow path in a bypass duct. A gear reduction is in driving engagement with the fan and has a gear reduction ratio of greater than 3.0 and less than 4.0. A low spool includes a low pressure turbine that drives a low pressure compressor and drives the gear reduction to drive the fan at a speed slower than the low pressure turbine. The low pressure compressor is a four-stage low pressure compressor. The low pressure turbine is a three-stage low pressure turbine. A high spool including a high pressure turbine that drives a high pressure compressor. The high pressure compressor is a nine-stage high pressure compressor. The high pressure turbine is a two-stage high pressure turbine. An exhaust gas exit temperature of greater than 900 degrees Fahrenheit and less than 1000 degrees Fahrenheit at maximum take-off.

Abstract: A system for controlling blade tip clearances in a gas turbine engine may comprise an active clearance control system and a controller in operable communication with the active clearance control system. The controller may be configured to identify a cruise condition, reduce a thrust limit of the gas turbine engine to a de-rated maximum climb thrust, determine a first target tip clearance based on the de-rated maximum climb thrust, and send a command signal correlating to the first target tip clearance to the active clearance control system.

Abstract: A method of operating a gas turbine engine includes commanding an acceleration of the gas turbine engine and moving a variable pitch high pressure compressor vane toward an open position thereby reducing an acceleration rate of a high pressure turbine rotor thereby reducing a change in a clearance gap between the high pressure turbine rotor and a blade outer airseal. An active clearance control system of a gas turbine engine includes an engine control system configured to command an acceleration of the gas turbine engine and move a variable pitch high pressure compressor vane toward an open position thereby slowing an acceleration rate of a high pressure turbine rotor thereby reducing a change in a clearance gap between the high pressure turbine rotor and a blade outer airseal located radially outboard of the high pressure turbine rotor.

Abstract: A system includes a gas turbine engine having a low speed spool and a high speed spool. The system also includes a spool coupling system configured to mechanically link the low speed spool and the high speed spool. A controller is operable to determine a mode of operation of the gas turbine engine, monitor for a spool coupling activation condition associated with the mode of operation, and activate the spool coupling system based on the controller detecting the spool coupling activation condition. Engagement and power transfer between the low speed spool and the high speed spool occurs based on activation of the spool coupling system and reaching an engagement condition of the spool coupling system.

Abstract: A gas turbine engine is defined wherein the inlet guide vanes leading into a core engine flow path are sized and positioned such that flow paths positioned circumferentially intermediate the vane are sufficiently large that a hydraulic diameter of greater than or equal to about 1.5 is achieved. This will likely reduce the detrimental effect of icing.

Abstract: A system for controlling blade tip clearances in a gas turbine engine may comprise an active clearance control system and a controller in operable communication with the active clearance control system. The controller may be configured to identify a cruise condition, reduce a thrust limit of the gas turbine engine to a de-rated maximum climb thrust, determine a first target tip clearance based on the de-rated maximum climb thrust, and send a command signal correlating to the first target tip clearance to the active clearance control system.

Abstract: A system includes a gas turbine engine having a low speed spool and a high speed spool. The system also includes a spool coupling system configured to mechanically link the low speed spool and the high speed spool. A controller is operable to determine a mode of operation of the gas turbine engine, monitor for a spool coupling activation condition associated with the mode of operation, and activate the spool coupling system based on the controller detecting the spool coupling activation condition. Engagement and power transfer between the low speed spool and the high speed spool occurs based on activation of the spool coupling system and reaching an engagement condition of the spool coupling system.

Abstract: A method of operating a gas turbine engine includes commanding an acceleration of the gas turbine engine and moving a variable pitch high pressure compressor vane toward an open position thereby reducing an acceleration rate of a high pressure turbine rotor thereby reducing a change in a clearance gap between the high pressure turbine rotor and a blade outer airseal. An active clearance control system of a gas turbine engine includes an engine control system configured to command an acceleration of the gas turbine engine and move a variable pitch high pressure compressor vane toward an open position thereby slowing an acceleration rate of a high pressure turbine rotor thereby reducing a change in a clearance gap between the high pressure turbine rotor and a blade outer airseal located radially outboard of the high pressure turbine rotor.