Abstract: A method of cooling a shroud ring in a turbine section of gas turbine engine includes identifying a series of alternating high temperature regions and lower temperature regions of a circumferential temperature distribution about the inner surface of the shroud ring, and impinging cooling air on to an outer surface of the shroud ring. More cooling air is impinged onto regions which correspond to the high temperature regions on the shroud ring than to regions corresponding to the lower temperature regions of the shroud ring.

Abstract: A turbine vane of a gas turbine engine is provided with a hollow core in the leading edge of the outer platform thereof. The core is interconnected with the leading edge core of the airfoil whereby to create a cooling air stream having a dual purpose and cooling both the leading edge of the outer platform and of the airfoil and thereby reducing cooling air consumption. The cooling air enters the core of the outer platform through an inlet port and exits through cooling holes provided in the leading edge of the airfoil.

Abstract: A blade outer air seal (BOAS) of a gas turbine engine has a segmented support ring to support a segmented turbine shroud. The support ring has a cooling air distribution system which includes a plurality of inlet cavities extending axially and inwardly to communicate with an inner cooling air passage within the respective support segments. The inlet cavities each are formed with two recesses defined in respective adjacent two support segments.

Abstract: In a turbine engine, low temperature air is diverted from a low pressure section of the compressor section of the engine to cool the high pressure turbine of the engine. Low pressure air is diverted from the compressor section, and its pressure is thereafter increased. Preferably, the pressure is increased in an intermediate cavity in the engine, where rotational energy of the diverted air is converted to static pressure by way of an obstruction that converts dynamic head of the air in the cavity into static pressure.

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 plenum defined with an outer skin and a perforated inner skin for receiving selective air flow to impinge a support case which supports shrouds of the rotor assemblies of the engine therein for active tip clearance control of the rotor assemblies. In one embodiment a bobbin-type transfer tube for supplying cooling air into the plenum, is provided between an outer case of the engine an the plenum such that the thermally induced relative movement of the outer case and the plenum is permitted.

Abstract: An apparatus for adjusting a thrust load on a rotor assembly of a gas turbine engine includes an impeller rear cavity defined between a rear face of an impeller of the rotor assembly and a stationary wall spaced axially apart from the rear surface of the impeller. A pressurized air flow with a tangential velocity is introduced into the impeller rear cavity at a tip of the impeller to pressurize the cavity. Means are provided in the cavity for directly interfering with the tangential velocity of the pressurized air flow to affect an average static pressure of the pressurized air flow within the cavity in order to adjust the thrust load on the rotor assembly caused by the average static pressure in the cavity.

Abstract: An access conduit for access to the interior of a combustor for the washing of the turbine components of a gas turbine engine. The access conduit is secured between a gas generator case and a combustion chamber liner of the combustor. The access conduit has an open outer end accessible from an outer face of the gas generator case and an open inner end exiting in a combustion chamber through the liner. The access conduit has one or more openings disposed in a combustor gap between the gas generator case and the liner of the combustor. A plug is removably secured in the open outer end and extends into the access conduit to obstruct the one or more openings.

Abstract: A fuel air heat exchanger for a gas turbine engine having fuel and air conduits in heat exchange relationship with one another, and a distribution conduit in heat exchange relationship with a component to be cooled. The distribution conduit is in fluid communication with the outlet of each air conduit. The heat exchanger also includes a secondary air inlet in fluid communication with the distribution conduit and a flow selection member selectively movable between first and second configurations. In the first configuration, the flow selection member closes the fluid communication between the secondary inlet and the distribution conduit. In the second configuration, the flow selection member opens the fluid communication between the secondary air inlet and the distribution conduit.

Abstract: A cooled turbine shroud segment for a gas turbine engine, having an axially extending shroud ring segment with an inner surface, an outer surface, an upstream flange and a downstream flange. The flanges mount the shroud ring within an engine casing. A perforated cooling air impingement plate is disposed on the outer surface of the shroud ring between the upstream flange and the downstream flange, with an impingement plenum defined between the impingement plate and the outer surface. Axially extending cooling bores in the ring segment extend between the impingement plenum and an outlet. A trough adjacent the outlet directs cooling air from the outlet towards a downstream stator vane to cool the stator vane.

Abstract: A deflector for redirecting cooling air leakage to improve the efficiency of a gas turbine engine rotors. Adjacent rotor blades have a radially extending gap between each adjacent rotor blade and cooling air leaks into the gaps resulting in engine inefficiency. A deflector, disposed circumferentially on a forward face of the coverplate, deflects cooling air leakage, flowing from the running seal through the cooling air leakage path, away from the gaps between the blades, onto the outward surface of the blade platform, and into the gaspath at an acute angle relative to rearwardly axial flow. A forwardly extending flange deflects cooling air leakage forwardly around the blade platform lip.

Abstract: A system for cooling a generator mounted in the tail-cone of an engine. The system comprises a fairing, which receives through an inlet thereof air from a bypass duct and directs the bypass air towards a cavity of the tail-cone for cooling the generator. The bypass air is then expelled through an outlet of a support strut positioned in fluid communication with the tail-cone cavity. The fairing inlet and the strut outlet are both positioned in a plane substantially perpendicular to a longitudinal plane of the engine. In this manner, circulation of the bypass air through the fairing, the tail-cone cavity, and the strut may be achieved. The bypass air directed through the fairing further enables cooling of service lines accommodated in the fairing. A lobe mixer is further used to direct the fairing and shield the latter from core exhaust.

Abstract: A centrifugal compressor having at least a diffuser is disclosed. The diffuser has an annular diffuser body having circumferentially spaced apart diffuser passages defining fluid paths through the diffuser body. The diffuser also has a plurality of diffusion members mounted to the annular diffuser body. Each diffusion member has a member inlet in fluid communication with a diffuser passage and a member outlet. Each diffusion member defines an aerodynamic throat disposed between the member inlet and the member outlet. The diffuser also has a fluid injection assembly with multiple injection conduits. Each injection conduit extends between a conduit inlet configured to receive a flow of compressible fluid from a supply and a conduit outlet communicating with a corresponding diffusion member downstream of the aerodynamic throat. The compressible fluid is injected through the conduit outlet into the diffusion members.

Abstract: A compressor for a gas turbine engine having a bleed air recirculation system includes a plurality of bleed holes extending through the shroud at a first axial location thereon substantially adjacent the blade tips. The bleed holes have a closed outer perimeter along their complete length. An annular bleed cavity surrounds the shroud and is in communication with outlet openings of the bleed holes. The bleed holes provide communication between said main gas flow passage and the bleed cavity. The bleed cavity includes exit passages having outlets disposed in said shroud at a second axial location which is upstream of both the first axial location and the leading edge of the blades of the rotor. Bleed air is passively bled from the main gas flow passage via the bleed holes, recirculated through the bleed cavity and re-injected back into the main gas flow passage at the second axial location.

Abstract: A gas turbine engine blade tip clearance control system and method is described. An annular housing is formed about an engine casing to which an annular shroud segment assembly is secured and closely spaced about blade tips of a stage of blades. The annular housing forms an air passage means communicating with the casing for directing a cooling air stream to the casing. A thermally operable passive ring valve is formed by two overlapped metal ring segments having a dissimilar coefficient of thermal expansion selected whereby to produce a radial gap between the ring segments when the valve temperature reaches a predetermined value. The radial gap admits a cooling air flow into the housing for cooling the casing and its associated shroud segment assembly to control radial growth and thereby prevent blade tip pinching.