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, 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 method of balancing a gas turbine engine rotor comprises the step of obtaining a rotor disc with a circumferential array of balance tabs projecting from a peripheral rim of the disc. Stress shielding scallops are defined in the rotor disc between the tabs. The balancing is achieved by removing material from at least one of the tabs.

Abstract: A gas turbine engine rotor including a disc adapted to be mounted for rotation about an axis, the disc including an annular balancing flange integrally connected thereto, the balancing flange having a first radial dimension around a first arc angle and a second radial dimension greater than the first radial dimension around a second arc angle, the second arc angle corresponding to 360 minus the first arc angle, the second arc angle being less than 180 degrees, the balancing flange around the second arc angle defining a protuberance, the protuberance being defined through machining of the balancing flange, the protuberance compensating for an unbalance of the rotor.

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 method of reducing stress concentration in a material subjected to a predominant stress in a direction parallel to an axial plane defined through an axis of a circular cylindrical hole in the material between a first material surface and a second material surface, the material having a material thickness defined between the first material surface and the second material surface, the method comprising: forming a first proximal recess in the first material surface on the axial plane having a depth less than the material thickness, the first proximal recess having an outer edge spaced a first proximal dimension in the axial plane from a first rim of the hole; and forming a second proximal recess in the second material surface on the axial plane having a depth less than the material thickness, the second proximal recess having an outer edge spaced a second proximal dimension in the axial plane from a second rim of the hole, wherein the first proximal dimension on the first material surface is diametrically oppo

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: 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 multi-hitch receiver assembly adapted for use on a trailer comprising a main frame that is adapted to be secured to the trailer, a means for securing the main frame to the trailer, and at least one receiver box assembly. The at least one receiver box assembly comprises a first member that is adapted to be secured to the main frame, a second member that is adapted to removably secure a first cargo carrier and is secured to the first member, and a third member that is adapted to removably secure a second cargo carrier and is secured to the second member. The at least one receiver box assembly is adapted to be secured to the main frame at more than one location on the main frame. A method comprising securing the main frame to the trailer.

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 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 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: 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: 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 method of reducing stress concentration in a material subjected to a predominant stress in a direction parallel to an axial plane defined through an axis of a circular cylindrical hole in the material between a first material surface and a second material surface, the material having a material thickness defined between the first material surface and the second material surface, the method comprising: forming a first proximal recess in the first material surface on the axial plane having a depth less than the material thickness, the first proximal recess having an outer edge spaced a first proximal dimension in the axial plane from a first rim of the hole; and forming a second proximal recess in the second material surface on the axial plane having a depth less than the material thickness, the second proximal recess having an outer edge spaced a second proximal dimension in the axial plane from a second rim of the hole, wherein the first proximal dimension on the first material surface is diametrically oppo

Abstract: A gas turbine airfoil blade comprises an airfoil having a leading edge and a trailing edge defining fore and aft points of an airfoil chord relative to a flowpath direction. The airfoil extends generally radially from a root to a tip, the root of the airfoil intersecting a platform of the blade. A body of the airfoil is composed of a plurality of airfoil sections stacked along a stacking line extending radially from the platform. A root airfoil section being the one of said airfoil sections intersecting the platform, the trailing edge at the root airfoil section extending to intersect the platform chordwise aft of the trailing edge of the airfoil section immediately radially outwardly adjacent to the root airfoil section.

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 gas turbine engine rotor including a disc adapted to be mounted for rotation about an axis, the disc including an annular balancing flange integrally connected thereto, the balancing flange having a first radial dimension around a first arc angle and a second radial dimension greater than the first radial dimension around a second arc angle, the second arc angle corresponding to 360 minus the first arc angle, the second arc angle being less than 180 degrees, the balancing flange around the second arc angle defining a protuberance, the protuberance being defined through machining of the balancing flange, the protuberance compensating for an unbalance of the rotor.