Abstract: A turbofan gas turbine engine includes a core engine within a core nacelle, a fan nacelle at least partially surrounding the core nacelle to define a bypass flow path and a variable fan nozzle exit area for bypass flow, and a pylon variable area flow system which operates to effect the bypass flow. A method of operating a turbofan gas turbine engine is also disclosed.

Abstract: A turbofan gas turbine engine includes a core engine within a core nacelle, a fan nacelle at least partially surrounding the core nacelle to define a bypass flow path and a variable fan nozzle exit area for bypass flow, and a pylon variable area flow system which operates to effect the bypass flow. A method of operating a turbofan gas turbine engine is also disclosed.

Abstract: A gas turbine engine includes a core engine defined about an axis, a gear system driven by the core engine, and a pylon variable area flow system. A fan is driven by the gear system. The variable area flow system operates to effect the bypass flow.

Abstract: A gas turbine engine according to an example of the present disclosure includes a fan situated at an inlet of a bypass passage. The fan has a fan diameter, Dfan. A low pressure turbine section is configured to drive the fan and a first compressor section. The low pressure turbine section has a greater number of stages than the first compressor section. The low pressure turbine section has a maximum rotor diameter, Dturb. A ratio of the maximum rotor diameter Dturb divided by the fan diameter Dfan is less than 0.6.

Abstract: A gas turbine engine includes a fan, a nacelle arranged about the fan, and an engine core at least partially within the nacelle. A fan bypass passage downstream of the fan between the nacelle and the gas turbine engine conveys a bypass airflow from the fan. A nozzle associated with the fan bypass passage is operative to control the bypass airflow. The nozzle includes a shape memory material having a first solid state phase that corresponds to a first nozzle position and a second solid state phase that corresponds to a second nozzle position.

Abstract: A gas turbine engine includes a first airflow structure and a second airflow structure disposed aft of the first airflow structure. The second airflow structure includes a leading edge region. A thickness of the leading edge region is based on a thickness of a wake in the airflow produced by the first airflow structure when the airflow passes between the first airflow structure and the second airflow structure.

Abstract: A rotor blade comprises an airfoil extending radially from a root section to a tip section and axially from a leading edge to a trailing edge, the leading and trailing edges defining a curvature therebetween. The curvature determines a relative exit angle at a relative span height between the root section and the tip section, based on an incident flow velocity at the leading edge of the airfoil and a rotational velocity at the relative span height. In operation of the rotor blade, the relative exit angle determines a substantially flat exit pressure ratio profile for relative span heights from 75% to 95%, wherein the exit pressure ratio profile is constant within a tolerance of 10% of a maximum value of the exit pressure ratio profile.

Abstract: A gas turbine engine includes a core engine defined about an axis, a gear system driven by the core engine, and a pylon variable area flow system. A fan is driven by the gear system. The variable area flow system operates to effect the bypass flow.

Abstract: A geared turbofan engine includes a first rotor, a fan, a second rotor, a gear train, a fan casing, a nacelle and a plurality of discrete acoustic liner segments. The fan is connected to the first rotor and is capable of rotation at frequencies between 200 and 6000 Hz and has a fan pressure ratio of between 1.25 and 1.60. The gear train connects the first rotor to the second rotor. The fan casing and nacelle are arranged circumferentially about a centerline and define a bypass flow duct in which the fan is disposed. The plurality of discrete acoustic liner segments with varied geometric properties are disposed along the bypass flow duct.

Abstract: A gas turbine engine includes a core engine defined about an axis, a gear system driven by the core engine, a fan, and a variable area flow system. The gear system defines a gear reduction ratio of greater than or equal to about 2.3. The fan is driven by the gear system about the axis to generate a bypass flow. The variable area flow system operates to effect the bypass flow.

Abstract: A gas turbine engine according to an example of the present disclosure includes a fan situated at an inlet of a bypass passage. The fan has a fan diameter, Dfan. A low pressure turbine section is configured to drive the fan and a first compressor section. The low pressure turbine section has a greater number of stages than the first compressor section. The low pressure turbine section has a maximum rotor diameter, Dturb. A ratio of the maximum rotor diameter Dturb divided by the fan diameter Dfan is less than 0.6.

Abstract: A gas turbine engine includes a fan, a nacelle arranged about the fan, and an engine core at least partially within the nacelle. A fan bypass passage downstream of the fan between the nacelle and the gas turbine engine conveys a bypass airflow from the fan. A nozzle associated with the fan bypass passage is operative to control the bypass airflow. The nozzle includes a shape memory material having a first solid state phase that corresponds to a first nozzle position and a second solid state phase that corresponds to a second nozzle position.

Abstract: A gas turbine engine (10) includes a fan (14), a nacelle (28) arranged about the fan, and an engine core at least partially within the nacelle. A fan bypass passage (30) downstream of the fan between the nacelle and the gas turbine engine conveys a bypass airflow (1) from the fan. A nozzle (40) associated with the fan bypass passage is operative to control the bypass airflow. The nozzle includes a shape memory material having a first solid state phase that corresponds to a first nozzle position and a second solid state phase that corresponds to a second nozzle position.

Abstract: A rotor blade comprises an airfoil extending radially from a root section to a tip section and axially from a leading edge to a trailing edge, the leading and trailing edges defining a curvature therebetween. The curvature determines a relative exit angle at a relative span height between the root section and the tip section, based on an incident flow velocity at the leading edge of the airfoil and a rotational velocity at the relative span height. In operation of the rotor blade, the relative exit angle determines a substantially flat exit pressure ratio profile for relative span heights from 75% to 95%, wherein the exit pressure ratio profile is constant within a tolerance of 10% of a maximum value of the exit pressure ratio profile.

Abstract: A geared turbofan engine includes a first rotor, a fan, a second rotor, a gear train, a fan casing, a nacelle and a plurality of discrete acoustic liner segments. The fan is connected to the first rotor and is capable of rotation at frequencies between 200 and 6000 Hz and has a fan pressure ratio of between 1.25 and 1.60. The gear train connects the first rotor to the second rotor. The fan casing and nacelle are arranged circumferentially about a centerline and define a bypass flow duct in which the fan is disposed. The plurality of discrete acoustic liner segments with varied geometric properties are disposed along the bypass flow duct.

Abstract: A gas turbine engine includes a spool and a turbine coupled to drive the spool. A fan is coupled to be driven by the turbine through the spool. A gear assembly is coupled between the fan and the spool such that rotation of the spool drives the fan at a different speed than the spool. A fan nozzle is located downstream from the fan. The fan nozzle includes a variable area nozzle configured to change an exit area of the fan nozzle. An acoustic liner partially lines the fan nozzle.

Abstract: A turbine engine system mounted on an aircraft wing includes a gas turbine engine having a spool, a turbine coupled with the spool, a fan coupled to be rotated about an axis through the spool, and a gear assembly coupled between the fan and spool such that rotation of the spool results in rotation of the fan at a different speed than the spool. The gas turbine engine is operable to discharge a jet plume that interacts with a flap of the aircraft wing. The gas turbine engine defines a design fan pressure ratio of 1.25-1.50 to control sound resulting from the jet plume that interacts with the flap.

Abstract: A rotor blade comprises an airfoil extending radially from a root section to a tip section and axially from a leading edge to a trailing edge, the leading and trailing edges defining a curvature therebetween. The curvature determines a relative exit angle at a relative span height between the root section and the tip section, based on an incident flow velocity at the leading edge of the airfoil and a rotational velocity at the relative span height. In operation of the rotor blade, the relative exit angle determines a substantially flat exit pressure ratio profile for relative span heights from 75% to 95%, wherein the exit pressure ratio profile is constant within a tolerance of 10% of a maximum value of the exit pressure ratio profile.

Abstract: A gas turbine engine includes a first airflow structure and a second airflow structure disposed aft of the first airflow structure. The second airflow structure includes a leading edge region. A thickness of the leading edge region is based on a thickness of a wake in the airflow produced by the first airflow structure when the airflow passes between the first airflow structure and the second airflow structure.

Abstract: A geared turbofan engine includes a first rotor, a fan, a second rotor, a gear train, a fan casing, a nacelle and a plurality of discrete acoustic liner segments. The fan is connected to the first rotor and is capable of rotation at frequencies between 200 and 6000 Hz and has a fan pressure ratio of between 1.25 and 1.60. The gear train connects the first rotor to the second rotor. The fan casing and nacelle are arranged circumferentially about a centerline and define a bypass flow duct in which the fan is disposed. The plurality of discrete acoustic liner segments with varied geometric properties are disposed along the bypass flow duct.