Abstract: There is disclosed a brush seal assembly including at least one annular bristle pack. The at least one annular bristle pack extends circumferentially around a central axis of the brush seal assembly. The at least one annular bristle pack has bristles extending along longitudinal axes from roots to free tips. The bristles extend toward a cylindrical plane of a the seal land. Projections of the free tips on the cylindrical plane define a bristle tip projection surface being non-axisymmetric. A method of operating a brush seal assembly is also disclosed.

Abstract: A method of operating a multi-engine aircraft includes operating a first engine of the aircraft to provide motive power; and operating a second engine of the aircraft in a standby mode to provide substantially no motive power, a rotor of the second engine having an idle rotational speed in the standby mode, and in the standby mode, sequentially executing cycles, a given cycle of the cycles including: opening a set of variable guide vanes upstream a compressor section of the second engine, spiking a rate of a fuel flow to a combustor of the second engine, the spiking and the opening timed to increase a rotational speed of the rotor of the second engine to an upper threshold above the idle rotational speed of the rotor, and in response to the rotational speed reaching the upper threshold, at least substantially closing the set of variable guide vanes.

Abstract: A brush seal assembly is adapted to be operatively mounted between a stator and a rotor of a gas turbine engine. The brush seal assembly comprises a housing and a seal operatively coupled to the housing. The seal comprises at least two annular brushes each having a plurality of bristles extending away from the housing. The at least two annular brushes and the housing defines a cavity therebetween. The housing defines at least one circumferential surface within the cavity. The housing comprises at least one discontinuity defined in the at least one circumferential surface. The at least one discontinuity disrupts a continuity of annularity of the circumferential surface.

Abstract: A gas turbine engine comprises a main gas path having an inner flow boundary wall and an outer flow boundary wall. A turbine exhaust case inner body defines a portion of the inner flow boundary wall of the main gas path. A lobed exhaust mixer defines a portion of the outer flow boundary wall of the main gas path. A stiffener ring is interconnected to at least a number lobes of the lobed exhaust mixer by a plurality of circumferentially spaced-apart struts extending through the main gas path. The stiffener ring is attached to the turbine exhaust case inner body by flexible features, such as circumferentially spaced-apart spring blades.

Abstract: There is disclosed a brush seal assembly including at least one annular bristle pack. The at least one annular bristle pack extends circumferentially around a central axis of the brush seal assembly. The at least one annular bristle pack has bristles extending along longitudinal axes from roots to free tips. The bristles extend toward a cylindrical plane of a the seal land. Projections of the free tips on the cylindrical plane define a bristle tip projection surface being non-axisymmetric. A method of operating a brush seal assembly is also disclosed.

Abstract: The stiffness of a rotor part is varied over its circumference to allow damper rings to effectively work in high speed applications. Circumferentially spaced-apart pockets may be defined in the rotor to create discontinuous strain to increase the force required to lock the damper ring in the groove above the centrifugal force of the ring when the rotor is rotating.

Abstract: A gas turbine engine comprises a main gas path having an inner flow boundary wall and an outer flow boundary wall. A turbine exhaust case inner body defines a portion of the inner flow boundary wall of the main gas path. A lobed exhaust mixer defines a portion of the outer flow boundary wall of the main gas path. A stiffener ring is interconnected to at least a number lobes of the lobed exhaust mixer by a plurality of circumferentially spaced-apart struts extending through the main gas path. The stiffener ring is attached to the turbine exhaust case inner body by flexible features, such as circumferentially spaced-apart spring blades.

Abstract: The stiffness of a rotor part is varied over its circumference to allow damper rings to effectively work in high speed applications. Circumferentially spaced-apart pockets may be defined in the rotor to create discontinuous strain to increase the force required to lock the damper ring in the groove above the centrifugal force of the ring when the rotor is rotating.

Abstract: An exhaust mixer arrangement for a gas turbine engine comprises an exhaust cone, a lobed exhaust mixer surrounding at least a portion of the exhaust cone and a cover mounted to an outer surface of the exhaust cone. The cover and the outer surface of the exhaust cone define a dead-end cavity for receiving a stiffener ring. A plurality of circumferentially spaced-apart struts interconnect at least a number of lobes of the lobed exhaust mixer to the stiffener ring.

Abstract: The application is directed to a brush seal assembly adapted to be operatively mounted between a stator and a rotor of a gas turbine engine. The brush seal assembly comprises a housing and a seal operatively coupled to the housing. The seal comprises at least two annular brushes each having a plurality of bristles extending away from the housing. The at least two annular brushes and the housing defines a cavity therebetween. The housing defines at least one circumferential surface within the cavity. The housing comprises at least one discontinuity defined in the at least one circumferential surface. The at least one discontinuity disrupts a continuity of annularity of the circumferential surface.

Abstract: The stiffness of a rotor part is varied over its circumference to allow damper rings to effectively work in high speed applications. Circumferentially spaced-apart pockets may be defined in the rotor to create discontinuous strain to increase the force required to lock the damper ring in the groove above the centrifugal force of the ring when the rotor is rotating.