Abstract: The gas turbine compressor for an aircraft gas turbine engine includes a compressor rotor having a plurality of compressor blades circumferentially distributed around a hub. Each of the compressor blades has an airfoil extending radially outward from the hub to a blade tip. A circumferential row of the compressor blades includes two or more different blade types, at least one modified blade of the two or more different blade types having means for generating different shock patterns between adjacent ones of the two or more different blade types when the gas turbine compressor operates in supersonic flow regimes. The means for generating different shock patterns on the modified blade aerodynamically mistune the two or more different blade types.

Abstract: There is disclosed a controlled gap seal for a gas turbine engine including a ring configured to be in a sealing engagement with a housing and a runner configured for rotation relative to the ring about the central axis. The runner has a runner face facing a ring face of the ring. The ring face is spaced apart from the runner face by a gap. A plurality of surface discontinuities are circumferentially distributed around the central axis on the runner face and/or the ring face. The plurality of surface discontinuities are spaced relative to one another such that a first set of adjacent surface discontinuities are circumferentially spaced from each other at a different distance than a second set of adjacent surface discontinuities. A method of using the controlled gap seal is disclosed.

Abstract: There is disclosed a controlled gap seal for a gas turbine engine. The seal has a ring annularly and continuously extending about a central axis. A runner that is configured for rotation about the central axis and rotatable relative to the ring. The runner has a face facing a face of the ring. The face of the ring is spaced apart from the face of the runner by a gap. Surface discontinuities are circumferentially distributed around the central axis. The surface discontinuities are located at specific locations and distributed in specific ways. A method of using the controlled gap seal is disclosed.

Abstract: There is disclosed an assembly for a gas turbine engine that includes a bearing housing circumferentially extending around a central axis thereof and delimiting a bearing cavity for receiving a bearing therein. A controlled gap seal is secured to the bearing housing, the controlled gap seal including a ring and a runner, the runner rotatable relative to the ring about the central axis, the runner spaced apart from the ring by a gap. The gap defines a fluid passage between the bearing cavity and an environment outside the bearing cavity. At least one baffle is secured to a surface of the bearing housing oriented toward the bearing cavity. The at least one baffle is a fin protruding from the surface and extending into the bearing cavity. The at least one baffle disrupts a cylindricality of the surface. A method of operating the bearing assembly is also disclosed.

Abstract: The gas turbine compressor for an aircraft gas turbine engine includes a compressor rotor having a plurality of compressor blades circumferentially distributed around a hub. Each of the compressor blades has an airfoil extending radially outward from the hub to a blade tip. A circumferential row of the compressor blades includes two or more different blade types, at least one modified blade of the two or more different blade types having means for generating different shock patterns between adjacent ones of the two or more different blade types when the gas turbine compressor operates in supersonic flow regimes. The means for generating different shock patterns on the modified blade aerodynamically mistune the two or more different blade types.

Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: The diffuser pipe assembly for a compressor of a gas turbine engine includes diffuser pipes circumferentially distributed around a central axis and configured for distributing a flow of compressed air from the compressor to the combustor. Each of the diffuser pipes curving between an inlet end and an outlet end. A first subset of the diffuser pipes has a natural vibration frequency different than a natural vibration frequency of at least a second subset of the diffuser pipes. A method of operating a compressor including the diffuser pipe assembly is also disclosed.

Abstract: A gas turbine engine and a method of tuning a rotor in the gas turbine engine wherein the rotor includes an array of blades extending from a rotor hub each having an airfoil mounted to a blade platform. The method includes adding or removing material from bladed rotor projections to alter the mass of the rotor and change the frequency of the respective airfoil.

Abstract: A compressor rotor, such as a fan, for a gas turbine engine is described which includes alternating at least first and second blade types. The leading edge of the second blade types includes a leading edge tip cutback extending to the blade tip thereof. The leading edge tip cutback of the second blade type defines a chord length at the blade tip of the second blade types that is less than that of the first blades types. The first and second blade types generate different shock patterns when the fan or compressor rotor operates in supersonic flow regimes.

Abstract: There is disclosed an assembly for a gas turbine engine that includes a bearing housing circumferentially extending around a central axis thereof and delimiting a bearing cavity for receiving a bearing therein. A controlled gap seal is secured to the bearing housing, the controlled gap seal including a ring and a runner, the runner rotatable relative to the ring about the central axis, the runner spaced apart from the ring by a gap. The gap defines a fluid passage between the bearing cavity and an environment outside the bearing cavity. At least one baffle is secured to a surface of the bearing housing oriented toward the bearing cavity. The at least one baffle is a fin protruding from the surface and extending into the bearing cavity. The at least one baffle disrupts a cylindricality of the surface. A method of operating the bearing assembly is also disclosed.

Abstract: The diffuser pipe assembly for a compressor of a gas turbine engine includes diffuser pipes circumferentially distributed around a central axis and configured for distributing a flow of compressed air from the compressor to the combustor. Each of the diffuser pipes curving between an inlet end and an outlet end. A first subset of the diffuser pipes has a natural vibration frequency different than a natural vibration frequency of at least a second subset of the diffuser pipes. A method of operating a compressor including the diffuser pipe assembly is also disclosed.

Abstract: There is disclosed a controlled gap seal for a gas turbine engine including a ring configured to be in a sealing engagement with a housing and a runner configured for rotation relative to the ring about the central axis. The runner has a runner face facing a ring face of the ring. The ring face is spaced apart from the runner face by a gap. A plurality of surface discontinuities are circumferentially distributed around the central axis on the runner face and/or the ring face. The plurality of surface discontinuities are spaced relative to one another such that a first set of adjacent surface discontinuities are circumferentially spaced from each other at a different distance than a second set of adjacent surface discontinuities. A method of using the controlled gap seal is disclosed.

Abstract: There is disclosed a controlled gap seal for a gas turbine engine. The seal has a ring annularly and continuously extending about a central axis. A runner that is configured for rotation about the central axis and rotatable relative to the ring. The runner has a face facing a face of the ring. The face of the ring is spaced apart from the face of the runner by a gap. Surface discontinuities are circumferentially distributed around the central axis. The surface discontinuities are located at specific locations and distributed in specific ways. A method of using the controlled gap seal is disclosed.

Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: A diffuser pipe for a gas turbine engine comprises a hollow pipe body including a first end, a second end fluidly connected to the first end, and at least one flattened area proximate to the second end. A ring is connected to the second end. The ring is an outlet of the diffuser pipe. At least one stiffener is disposed on the at least one flattened area. The ring and the at least one stiffener reduce vibratory stresses at the second end of the pipe body. A method of manufacturing a diffuser pipe of a gas turbine engine is also presented.

Abstract: A rotor blade vibration damper for a gas turbine engine includes an elongated damper body including a top portion extending longitudinally between a front end and a rear end. The top portion has a width defined between spaced apart lateral sides and is substantially flat between the front and rear ends and between the lateral sides such as to define a longitudinal plane within which the top portion lies. A front tab extends downwardly from the front end of the top portion relative to the longitudinal plane. The rear end of the top portion is flat and generally contained in the longitudinal plane. A pair of lateral tabs extends downwardly from each of said lateral sides of the top portion relative to the longitudinal plane.

Abstract: A compressor rotor, such as a fan, for a gas turbine engine is described which includes alternating at least first and second blade types. The leading edge of the second blade types includes a leading edge tip cutback extending to the blade tip thereof. The leading edge tip cutback of the second blade type defines a chord length at the blade tip of the second blade types that is less than that of the first blades types. The first and second blade types generate different shock patterns when the fan or compressor rotor operates in supersonic flow regimes.

Abstract: A compressor rotor for a gas turbine engine is described which includes sets of blades having different airfoil thickness distributions, each including a frequency modifier forming a thickness differential relative to a baseline blade thickness. The frequency modifiers provide different natural vibration frequencies for each of the blades, and facilitate modifying natural vibration frequency separation between adjacent blades of the compressor rotor.

Abstract: A gas turbine engine and a method of tuning a rotor in the gas turbine engine wherein the rotor includes an array of blades extending from a rotor hub each having an airfoil mounted to a blade platform. The method includes adding or removing material from bladed rotor projections to alter the mass of the rotor and change the frequency of the respective airfoil.