Abstract: An impeller for a centrifugal compressor, the impeller rotatable about a central axis, has: an outer hub body including a first material and extending around the central axis, the outer hub body defining a gaspath face extending from an inlet to an outlet, the gaspath face extending radially away from the central axis from the inlet to the outlet; blades protruding from the gaspath face and circumferentially distributed around the central axis; and an inner hub body extending around the central axis, the inner hub body secured to the outer hub body, the outer hub body axially overlapping and extending around the inner hub body, the inner hub body made of a second material being more cold dwell resistant than the first material.

Abstract: An impeller for a centrifugal compressor, the impeller rotatable about a central axis, has: an outer hub body including a first material and extending around the central axis, the outer hub body defining a gaspath face extending from an inlet to an outlet, the gaspath face extending radially away from the central axis from the inlet to the outlet; blades protruding from the gaspath face and circumferentially distributed around the central axis; and an inner hub body extending around the central axis, the inner hub body secured to the outer hub body, the outer hub body axially overlapping and extending around the inner hub body, the inner hub body made of a second material being more cold dwell resistant than the first material.

Abstract: A rotary assembly for an aircraft engine is disclosed. A shaft is mounted for rotation about a central axis and a rotary part is mounted on the shaft for common rotation therewith. The rotary part has an axial end portion extending away from a center of mass of the rotary part, the axial end portion having a radial thickness smaller than that of the rotary part at an axial location aligned with the center of mass. The shaft and the rotary part have an interface defining an interference fit between the shaft and the axial end portion of the rotary part. The interface is located at a distance along the central axis from the center of mass. An undercut is defined in the rotary part. The undercut extends axially from adjacent the interface towards the center of mass.

Abstract: A method of operating an aircraft engine having a bladed rotor coupled thereto during an icing condition is provided. The method comprises controlling the aircraft engine to alternatingly achieve an ice accretion rotational speed of the bladed rotor at which ice accretion on blades of the bladed rotor occurs, and a reduced rotational speed of the bladed rotor to promote ice shedding from the blades of the bladed rotor. The reduced rotational speed is lower than the ice accretion rotational speed.

Abstract: A rotary assembly for an aircraft engine is disclosed. A shaft is mounted for rotation about a central axis and a rotary part is mounted on the shaft for common rotation therewith. The rotary part has an axial end portion extending away from a center of mass of the rotary part, the axial end portion having a radial thickness smaller than that of the rotary part at an axial location aligned with the center of mass. The shaft and the rotary part have an interface defining an interference fit between the shaft and the axial end portion of the rotary part. The interface is located at a distance along the central axis from the center of mass. An undercut is defined in the rotary part. The undercut extends axially from adjacent the interface towards the center of mass.

Abstract: A method of operating an aircraft engine having a bladed rotor coupled thereto during an icing condition is provided. The method comprises controlling the aircraft engine to alternatingly achieve an ice accretion rotational speed of the bladed rotor at which ice accretion on blades of the bladed rotor occurs, and a reduced rotational speed of the bladed rotor to promote ice shedding from the blades of the bladed rotor. The reduced rotational speed is lower than the ice accretion rotational speed.

Abstract: A compressor rotor for a gas turbine engine includes a hub disposed about an axis of rotation and an outer surface forming a radially inner gaspath boundary, the outer surface defining a nominal hub diameter. A circumferential array of blades extends radially outwardly from the hub. A first inter-blade passage is defined between a first set of adjacent blades and has a first throat area. A second inter-blade passage is defined between a second set of adjacent blades and has a second throat area that is smaller than the first throat area. At least one scoop is disposed in the second inter-blade passage, the scoop defining a cavity extending radially into the outer surface of the hub relative to the nominal hub diameter.

Abstract: A rotor for a gas turbine engine. The rotor includes blades circumferentially distributed around a hub. The blades have airfoils with a span defined between a root and tip, a chord defined between a leading edge and a trailing edge, and a thickness defined between a pressure side surface and suction side surface. The blades include first blades and second blades. The airfoil of the first blades has a first thickness distribution defining a first natural vibration frequency of the airfoils of the first blades. The airfoil of the second blades has a second thickness distribution defining a second natural vibration frequency different than the first natural vibration frequency. The first thickness distribution is different than the second thickness distribution along a radially-inner half of the span, and the first thickness distribution matches the second thickness distribution along a radially-outer half of the span.

Abstract: An inlet for a turbofan engine, including an inlet wall surrounding an inlet flow path. The inlet wall extends axially from an upstream end to a downstream end adjacent the fan. The inlet wall has a shape defining a plurality of teeth circumferentially spaced around the inlet. The teeth extend axially and project radially inwardly toward the central longitudinal axis. A central portion of the inlet flow path has a cross-sectional dimension measured diametrically between opposed teeth, the cross-sectional dimension varying along the axial direction. The central portion defines a geometric throat at a minimum value of the cross-sectional dimension. The inlet wall is shaped so that the geometric throat is axially spaced from the upstream end and the downstream end. A gas turbine engine and a method of shielding tips of fan blades from impact by an object having a predetermined minimum dimension are also discussed.

Abstract: A fan for a gas turbine engine comprises blades distributed around a hub. The blades include first and second blades, having geometric parameters and/or material properties that differ from each other to frequency mistune the fan. The blades are distributed about the hub with at least one second blade between adjacent first blades. The leading edge of the airfoil of the second blades is disposed axially aft of the corresponding leading edge of the first blades in at least a portion of the blade span.

Abstract: Mistuned bladed rotors and associated manufacturing methods are disclosed. An exemplary method includes forming two or more blades of the bladed rotor where the two or more blades have substantially identical external aerodynamic surfaces and have different internal configurations causing the two or more blades to have different natural frequencies.

Abstract: A compressor rotor for a gas turbine engine has blades circumferentially distributed around and extending a span length from a central hub. The blades include alternating first and second blades having airfoils with corresponding geometric profiles. The airfoil of the first blade has a coating varying in thickness relative to the second blade to provide natural vibration frequencies different between the first and the second blades.

Abstract: A compressor rotor for a gas turbine engine has blades circumferentially distributed around and extending a span length from a central hub. The blades include alternating first and second blades having airfoils with corresponding geometric profiles. The airfoil of the first blade has a coating varying in thickness relative to the second blade to provide natural vibration frequencies different between the first and the second blades.

Abstract: A rotor disc for a gas turbine engine includes an annular disc body configured to support a circumferential array of blades and having a plurality of passages defined therethrough. The passages form coils within the disc body and/or have a packing density of at least 0.1 in cross-sectional plane containing the central axis, the packing density being defined by a ratio between an open area of the passages and a solid area of the disc in the cross-sectional plane. A method of manufacturing a rotor disc is also discussed.

Abstract: A compressor rotor for a gas turbine engine has blades circumferentially distributed around and extending a span length from a central hub. The blades include alternating first and second blades having airfoils with corresponding geometric profiles. The airfoil of the first blade has a coating varying in thickness relative to the second blade to provide natural vibration frequencies different between the first and the second blades.

Abstract: A rotor for a gas turbine engine comprises a rotor having a hub and blades around the hub, and extending from the hub to tips. The tips include first and second tip portions between their respective tip leading edge and tip trailing edge. Tips are spaced from a rotational axis of the rotor by spans. A mean span of a first tip portion of a first blade is greater than a mean span of a corresponding first tip portion of a second blade. A mean span of a second tip portion the first blade is less than a mean span of a corresponding second tip portion of the second blade.

Abstract: The gas turbine engine rotor can have a body having a solid-of-revolution-shaped portion centered around a rotation axis, the body defining an annular cavity centered around the rotation axis, the annular cavity penetrating into the body from an annular opening, the annular cavity extending between two opposite annular wall portions each leading to a corresponding edge of the opening; and at least one structural plate mounted to and extending between the two opposite annular wall portions and forming an interference fit therewith.

Abstract: A fan for a gas turbine engine comprises blades distributed around a hub. The blades include first and second blades, having geometric parameters and/or material properties that differ from each other to frequency mistune the fan. The blades are distributed about the hub with at least one second blade between adjacent first blades. The leading edge of the airfoil of the second blades is disposed axially aft of the corresponding leading edge of the first blades in at least a portion of the blade span.

Abstract: A rotor for a gas turbine engine. The rotor includes blades circumferentially distributed around a hub. The blades have airfoils with a span defined between a root and tip, a chord defined between a leading edge and a trailing edge, and a thickness defined between a pressure side surface and suction side surface. The blades include first blades and second blades. The airfoil of the first blades has a first thickness distribution defining a first natural vibration frequency of the airfoils of the first blades. The airfoil of the second blades has a second thickness distribution defining a second natural vibration frequency different than the first natural vibration frequency. The first thickness distribution is different than the second thickness distribution along a radially-inner half of the span, and the first thickness distribution matches the second thickness distribution along a radially-outer half of the span.

Abstract: A compressor rotor for a gas turbine engine includes a hub disposed about an axis of rotation and an outer surface forming a radially inner gaspath boundary, the outer surface defining a nominal hub diameter. A circumferential array of blades extends radially outwardly from the hub. A first inter-blade passage is defined between a first set of adjacent blades and has a first throat area. A second inter-blade passage is defined between a second set of adjacent blades and has a second throat area that is smaller than the first throat area. At least one scoop is disposed in the second inter-blade passage, the scoop defining a cavity extending radially into the outer surface of the hub relative to the nominal hub diameter.