Abstract: A variable guide vane (VGV) assembly, has: a casing enclosing a cavity and defining apertures distributed around a central axis; variable guide vanes (VGVs) distributed around the central axis and having an airfoil portion extending from a first end to a second end along a pivot axis, and a shaft portion pivotably received within the apertures; vane drive members secured to the shaft portions of the VGVs and located within the cavity, a unison transmission member within the cavity and rotatable about the central axis and engaged to the vane drive members, and an external mechanism secured to the second end of one of the VGVs and disposed outside the cavity, the external mechanism engageable by an actuator for rotating the one of the VGVs about its pivot axis, thereby rotating the unison transmission member, which, in turn, drives a remainder of the VGVs in rotation.

Abstract: A turbomachine airfoil element comprises an airfoil having: an inboard end; an outboard end; a leading edge; a trailing edge; a pressure side; and a suction side. A span between the inboard end and the outboard end is 1.75-2.20 inches. A chord length at 50% span is 1.05-1.35 inches. At least two of: a first mode resonance frequency is 2400±10% Hz; a second mode resonance frequency is 4950±10% Hz; a third mode resonance frequency is 7800±10% Hz; a fourth mode resonance frequency is 8700±10% Hz; and a fifth mode resonance frequency is 12500±10% Hz.

Abstract: A variable guide vane (VGV) assembly, has: a casing enclosing a cavity and defining apertures distributed around a central axis; variable guide vanes (VGVs) distributed around the central axis and having an airfoil portion extending from a first end to a second end along a pivot axis, and a shaft portion pivotably received within the apertures; vane drive members secured to the shaft portions of the VGVs and located within the cavity, a unison transmission member within the cavity and rotatable about the central axis and engaged to the vane drive members, and an external mechanism secured to the second end of one of the VGVs and disposed outside the cavity, the external mechanism engageable by an actuator for rotating the one of the VGVs about its pivot axis, thereby rotating the unison transmission member, which, in turn, drives a remainder of the VGVs in rotation.

Abstract: The gas turbine engine can have a gas path extending in serial flow communication across a compressor, a combustion chamber, and a turbine, the turbine having at least one multistage turbine section having a front toward the combustion chamber and a rear opposite the front, a plenum radially outward of the gas path, and a plurality of aperture sets interspaced from one another between the front and the rear, the aperture sets providing fluid flow communication from the plenum to the gas path, and a cooling air path having an outlet fluidly connected to the plenum at the rear of the plenum.

Abstract: A gas turbine engine includes an annular casing and a plurality of shroud segments forming an annular shroud. The annular shroud forms with the annular casing an annular cavity therebetween. The annular cavity includes an inlet and an outlet. An annular ring assembly is disposed in the annular cavity between the casing and the shroud and cooperating therewith to provide a first annular chamber and a second annular chamber. The annular ring assembly and a first portion of the shroud form the first annular chamber. The annular ring assembly and a second portion of the shroud form the second annular chamber. The annular ring assembly forms an intermediate annular chamber disposed between the first annular chamber and the second annular chamber. A flow path for coolant air is sequentially defined through the inlet, the first annular chamber, the intermediate annular chamber, the second annular chamber and the outlet.

Abstract: The gas turbine engine can have a gas path extending in serial flow communication across a compressor, a combustion chamber, and a turbine, the turbine having at least one multistage turbine section having a front toward the combustion chamber and a rear opposite the front, a plenum radially outward of the gas path, and a plurality of aperture sets interspaced from one another between the front and the rear, the aperture sets providing fluid flow communication from the plenum to the gas path, and a cooling air path having an outlet fluidly connected to the plenum at the rear of the plenum.

Abstract: A shroud sealing arrangement for a gas turbine engine, which comprises a static shroud assembly mounted to an engine case and having a platform surrounding a rotatable airfoil array. The platform has an inner side and an outer side and extends from a leading edge to a trailing edge. A shroud support structure mounts the shroud platform to the case. A circumferential groove is defined on the outer side of the shroud platform proximal to one of the leading edge and the trailing edge. A sealing ring is set in the groove and adapted to seal cooling air from escaping directly to the gas path.

Abstract: A multi-lobe exhaust mixer has an annular body composed of a plurality of circumferentially adjacent lobe segments. The lobe segments may be made of a ceramic matrix composite material to reduce the weight of the mixer and ensure proper behavior when exposed to high thermal gradients. Each lobe segment may have partial lobes at circumferentially opposed ends thereof and at least one complete lobe therebetween. The partial lobes of the circumferentially adjacent lobe segments combining to conjointly form complete lobes at the junction between the circumferentially adjacent lobe segments. The partial lobes may be nested into each other to dampen vibrations.

Abstract: A shroud sealing arrangement for a gas turbine engine, which comprises a static shroud assembly mounted to an engine case and having a platform surrounding a rotatable airfoil array. The platform has an inner side and an outer side and extends from a leading edge to a trailing edge. A shroud support structure mounts the shroud platform to the case. A circumferential groove is defined on the outer side of the shroud platform proximal to one of the leading edge and the trailing edge. A sealing ring is set in the groove and adapted to seal cooling air from escaping directly to the gas path.

Abstract: A shroud sealing arrangement for a gas turbine engine, which comprises a static shroud assembly mounted to an engine case and having a platform surrounding a rotatable airfoil array. The platform has an inner side and an outer side and extends from a leading edge to a trailing edge. A shroud support structure mounts the shroud platform to the case. A circumferential groove is defined on the outer side of the shroud platform proximal to one of the leading edge and the trailing edge. A sealing ring is set in the groove and adapted to seal cooling air from escaping directly to the gas path.

Abstract: A gas turbine engine includes an annular casing and a plurality of shroud segments forming an annular shroud. The annular shroud forms with the annular casing an annular cavity therebetween. The annular cavity includes an inlet and an outlet. An annular ring assembly is disposed in the annular cavity between the casing and the shroud and cooperating therewith to provide a first annular chamber and a second annular chamber. The annular ring assembly and a first portion of the shroud form the first annular chamber. The annular ring assembly and a second portion of the shroud form the second annular chamber. The annular ring assembly forms an intermediate annular chamber disposed between the first annular chamber and the second annular chamber. A flow path for coolant air is sequentially defined through the inlet, the first annular chamber, the intermediate annular chamber, the second annular chamber and the outlet.

Abstract: A gas turbine engine includes an annular casing and a plurality of shroud segments forming an annular shroud. The annular shroud forms with the annular casing an annular cavity therebetween. The annular cavity includes an inlet and an outlet. An annular ring assembly is disposed in the annular cavity between the casing and the shroud and cooperating therewith to provide a first annular chamber and a second annular chamber. The annular ring assembly and a first portion of the shroud form the first annular chamber. The annular ring assembly and a second portion of the shroud form the second annular chamber. The annular ring assembly forms an intermediate annular chamber disposed between the first annular chamber and the second annular chamber. A flow path for coolant air is sequentially defined through the inlet, the first annular chamber, the intermediate annular chamber, the second annular chamber and the outlet.

Abstract: A multi-lobe exhaust mixer has an annular body composed of a plurality of circumferentially adjacent lobe segments. The lobe segments may be made of a ceramic matrix composite material to reduce the weight of the mixer and ensure proper behavior when exposed to high thermal gradients. Each lobe segment may have partial lobes at circumferentially opposed ends thereof and at least one complete lobe therebetween. The partial lobes of the circumferentially adjacent lobe segments combining to conjointly form complete lobes at the junction between the circumferentially adjacent lobe segments. The partial lobes may be nested into each other to dampen vibrations.

Abstract: A shroud sealing arrangement for a gas turbine engine, which comprises a static shroud assembly mounted to an engine case and having a platform surrounding a rotatable airfoil array. The platform has an inner side and an outer side and extends from a leading edge to a trailing edge. A shroud support structure mounts the shroud platform to the case. A circumferential groove is defined on the outer side of the shroud platform proximal to one of the leading edge and the trailing edge. A sealing ring is set in the groove and adapted to seal cooling air from escaping directly to the gas path.

Abstract: A gas turbine engine includes an annular casing and a plurality of shroud segments forming an annular shroud. The annular shroud forms with the annular casing an annular cavity therebetween. The annular cavity includes an inlet and an outlet. An annular ring assembly is disposed in the annular cavity between the casing and the shroud and cooperating therewith to provide a first annular chamber and a second annular chamber. The annular ring assembly and a first portion of the shroud form the first annular chamber. The annular ring assembly and a second portion of the shroud form the second annular chamber. The annular ring assembly forms an intermediate annular chamber disposed between the first annular chamber and the second annular chamber. A flow path for coolant air is sequentially defined through the inlet, the first annular chamber, the intermediate annular chamber, the second annular chamber and the outlet.

Abstract: A turbine blade for a gas turbine engine with an airfoil portion defined by a perimeter wall surrounding at least one enclosure, the perimeter wall having a plurality of cooling holes defined therethrough and providing fluid communication between the at least one enclosure and a gaspath of the gas turbine engine. The plurality of cooling holes includes at least one row of holes selected from the group consisting of a first row, a second row, a third row and a fourth row, with the first, second, third and fourth rows of holes respectively including the holes numbered PA-1 to PA-10, PB-1 to PB-3, HA-1 to HA-9, and SA-1 to SA-8 located such that a central axis thereof extends through the respective point 1 and point 2 having a nominal location in accordance with the X, Y, Z Cartesian coordinate values set forth in Table 3.

Abstract: A rotor retaining system for a rotor assembly of a gas turbine engine includes a washer interlocking multiple retaining nuts to prevent relative rotation. The retaining nuts retain a rotor disc and a cover plate in position, respectively. A wire is provided to retain the washer in position and which may dampen vibration during engine operation.

Abstract: A gas turbine engine case having a working fluid flow, includes inner and outer case portions defining an annular duct for directing the working fluid flow, and a plurality of struts positioned within the annular duct and extending between the inner and outer case portions. The struts are welded to the inner and outer case portions with a first weld along a peripheral line of the respective struts and with second weld, of fillet type, in selected locations for additionally connecting a portion of each strut to the respective inner and outer case portions.

Abstract: A rotor retaining system for a rotor assembly of a gas turbine engine includes a washer interlocking multiple retaining nuts to prevent relative rotation. The retaining nuts retain a rotor disc and a cover plate in position, respectively. A wire is provided to retain the washer in position and which may dampen vibration during engine operation.

Abstract: A gas turbine engine case having a working fluid flow, includes inner and outer case portions defining an annular duct for directing the working fluid flow, and a plurality of struts positioned within the annular duct and extending between the inner and outer case portions. The struts are welded to the inner and outer case portions with a first weld along a peripheral line of the respective struts and with second weld, of fillet type, in selected locations for additionally connecting a portion of each strut to the respective inner and outer case portions.