Abstract: A core nacelle for a gas turbine engine, according to an exemplary aspect of the present disclosure includes, among other things, a core cowl positioned adjacent to an inner duct boundary of a fan bypass passage having an associated cross-sectional area that radially extends between a fan exhaust nozzle and the inner duct boundary. The core cowl includes at least one groove that is selectively exposed to change the cross-sectional area at an axial location of the fan exhaust nozzle.

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 turbofan engine pylon structure has a fan variable area nozzle defined by a variable area flow system between a pylon intake and a pylon exhaust to selectively adjust a bypass flow through the pylon structure. The variable area flow system changes the physical area and geometry of a pylon nozzle exit area to manipulate the bypass flow by opening and closing an additional flow area of the variable area flow system.

Abstract: A core nacelle for a gas turbine engine, according to an exemplary aspect of the present disclosure includes, among other things, a core cowl positioned adjacent to an inner duct boundary of a fan bypass passage having an associated cross-sectional area that radially extends between a fan exhaust nozzle and the inner duct boundary. The core cowl includes at least one groove that is selectively exposed to change the cross-sectional area at an axial location of the fan exhaust nozzle.

Abstract: An example core nacelle for a gas turbine engine includes a core cowl positioned adjacent to an inner duct boundary of a fan bypass passage having an associated cross-sectional area. The core cowl includes at least one groove that is selectively exposed to change the cross-sectional area.

Abstract: A turbofan engine includes a fan variable area nozzle having a multiple of vents through a fan nacelle and a sleeve system movable relative to the vents by an actuator system. The fan variable area nozzle changes the effective area of the fan nozzle exit area to permit efficient operation at predefined pressure ratios. The vents include a grid structure which directs and smoothes the airflow therethrough as well as to reduce noise generation.

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: An example core nacelle for a gas turbine engine includes a core cowl positioned adjacent to an inner duct boundary of a fan bypass passage having an associated cross-sectional area. The core cowl includes at least one groove that is selectively exposed to change the cross-sectional area.

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 turbofan engine includes a fan variable area nozzle having a multiple of vents through a fan nacelle and a sleeve system movable relative to the vents by an actuator system. The fan variable area nozzle changes the effective area of the fan nozzle exit area to permit efficient operation at predefined pressure ratios. The vents include a grid structure which directs and smoothes the airflow therethrough as well as to reduce noise generation.

Abstract: A turbofan engine pylon structure having a fan variable area nozzle defined by a variable area flow system between a pylon intake and a pylon exhaust to selectively adjust a bypass flow. The variable area flow system changes the physical area and geometry of a fan nozzle exit area to manipulate the bypass flow by opening and closing an additional flow area of the variable area flow system.