Abstract: A rotor assembly for a gas turbine engine includes a rotor disk. The rotor disk includes a heat barrier feature radially inward of a rotor blade and radially outward of a rotor disk.

Abstract: A rotor assembly for a gas turbine engine includes a rotor disk. The rotor disk includes a heat barrier feature radially inward of a rotor blade and radially outward of a rotor disk.

Abstract: A rotor assembly for a gas turbine engine includes a rotor disk. The rotor disk includes a heat barrier feature radially inward of a rotor blade and radially outward of a rotor disk.

Abstract: A method is provided for engineering a single crystal cast gas turbine engine first component for cooperating with a second component. An at least local first operational stress on the first component is determined. The first operational stress has a first direction. A crystal orientation within the component or a physical configuration of the component is selected so that the first operational stress produces a desired engagement of the first component with the second component associated with either a negative Poisson's effect or high Poisson's effect in a second direction. Single crystal or highly textured iron- and nickel-base alloys enable one to use such effect in high temperature and/or corrosive environments.

Abstract: A method is provided for engineering a single crystal cast gas turbine engine first component for cooperating with a second component. An at least local first operational stress on the first component is determined. The first operational stress has a first direction. A crystal orientation within the component or a physical configuration of the component is selected so that the first operational stress produces a desired engagement of the first component with the second component associated with either a negative Poisson's effect or high Poisson's effect in a second direction. Single crystal or highly textured iron- and nickel-base alloys enable one to use such effect in high temperature and/or corrosive environments.

Abstract: A stator assembly for a rotary machine having an array of wall segments for bounding a working medium flow path is disclosed. Various construction details which provide a sealing structure for the segments are developed. In one detailed embodiment, a removable seal retainer for a seal chamber bounded by wall segments traps a resilient seal member in the seal chamber. In one particular embodiment, a modular subassembly for the engine is an outer air assembly disposed in a fixture as the subassembly is assembled.

Abstract: A gas turbine engine generally includes a compressor, a combustor, and a turbine. The turbine can include an integrated manifold comprising a plenum defined by a manifold disposed in connection with a divider plate and opposite a shielding plate comprising a plurality of apertures. During operation of the gas turbine engine, a quantity of working fluid enters the integrated manifold and circulates throughout the plenum and shielding plate, and enters the turbine through the apertures to actively control clearances between turbine engine components.

Abstract: The invention is a method for controlling blade tip clearance in a turbine engine having a flowpath extending therethrough, and a system for carrying out the method. The method includes acquiring a first nonpulsating pressure signal PC representative of tip clearance, sensing a second pressure PB substantially unaffected by tip clearance, forming an actual ratio of the acquired pressure and the sensed pressure, determining an error E having an actual component and a desired component, the actual component being a function of the actual ratio; and commanding a clearance control system to reduce the error.

Abstract: The invention is a method for controlling blade tip clearance in a turbine engine having a flowpath extending therethrough, and a system for carrying out the method. The method includes acquiring a first nonpulsating pressure signal PC representative of tip clearance, sensing a second pressure PB substantially unaffected by tip clearance, forming an actual ratio of the acquired pressure and the sensed pressure, determining an error E having an actual component and a desired component, the actual component being a function of the actual ratio; and commanding a clearance control system to reduce the error.

Abstract: A system and method of controlling clearance in a turbomachine includes adjusting the machine case cooling air in response to the difference between the desired clearance and the actual clearance. An accurate estimate of the actual clearance is made with a real time mathematical model on-board engine controller. The model computes thermal growth of the turbomachine components each with a difference equation derived from a closed form solution to the 1st order differential equation obtained through the application of 1st law of thermodynamics. The resulting equation is conveniently formulated in terms of equivalent time constant and steady state growth both correlated with thermo-physical characteristics of multiple fluid streams exchanging heat with the component. The solution is applied over a time step of the control software. Approximating coefficients are strategically placed in the model to allow calibration of the model to a particular version of the engine hardware.

Abstract: A method of designing an outer air seal for the turbine blades of a gas turbine engine utilizes a knowledge-based product model software program for generating a parametric, three-dimensional, geometric model of the air seal. The product model software program is embodied in a knowledge-based engineering system. The model is created by the program through user selection of various structural feature options available for the air seal. The product model software program uses its internal knowledge base of configuration dependent parameter relationships and rules to design the model. Various types of analyses may then be run to validate the model. The model may be changed, if necessary, as a result of the analyses. The air seal model output from the product model software program is in a file format that defines the topology and dimensions of the geometry of the air seal.

Abstract: A coolable stator vane 46 having a platform 48, 54 having internal cooling for the platform is disclosed. Various construction details are developed for cooling the interior of the platform in the trailing edge region 126, 146 of the platform. In one particular embodiment, the platform has a two-pass passage 168 in flow communication with the exterior of the platform, the rearmost pass 170 discharging more than half the cooling fluid entering the two pass passage.

Abstract: A shroud segment for a gas turbine engine includes a rail engaged with adjacent support structure to retain the segment and to provide sealing between the segment and the adjacent structure. Various construction details are disclosed which provide an effective sealing and retaining feature that permits differing thermal growth between the segment and the support structure. In a particular embodiment, a shroud segment includes a rail along a forward edge. The rail is engaged with a recess in the support structure to retain the segment and with a band which positions the segment and seals the forward edge.

Abstract: A shroud for a rotor assembly is provided comprising a mounting ring, an aft seal ring, a forward seal ring, and a blade outer air seal. The mounting ring is fixed within the casing surrounding the rotor assembly, and includes a first attachment apparatus. The blade outer air seal includes a plurality of body segments. Each body segment includes a first face, a second face, a plurality of passages for receiving cooling air disposed between the faces, a second attachment apparatus, and a post for biasing each the body segment in contact with the aft seal ring. The first and second attachment apparatus cooperate to suspend the blade outer seal segments in close proximity to the rotor assembly.

Abstract: A turbine shroud segment for use in a gas turbine engine includes a serpentine channel along at least one axial edge of the segment. Various construction details are developed that disclose a channel for efficiently flowing cooling fluid through an axial edge of a shroud segment. In a particular embodiment, a turbine shroud segment includes a leading edge serpentine channel having a bend passage which includes a purge hole to avoid separating flow in the bend passage.

Abstract: A turbine shroud segment for use in a gas turbine engine includes a serpentine channel along at least one axial edge of the segment. Various construction details are developed that disclose a channel for efficiently flowing cooling fluid through an axial edge of a shroud segment. In a particular embodiment, a turbine shroud segment includes a leading edge serpentine channel and a trailing edge serpentine channel. Both serpentine channels include ducts that extend to the serpentine channels from a point inward of adjacent retaining hooks. Cooling fluid flowing onto the outward surface of the segments flows through the ducts and along the serpentine channels to cool the leading and trailing edges of the segments.

Abstract: A coolable outer air seal assembly for a gas turbine engine is disclosed. Various construction details are developed which provide an outer air seal assembly comprised of a plurality of seal segments including bumpers adapted to maintain adequate cooling fluid flow through the clearance gap between adjacent seal segments. In one particular embodiment, each seal segment includes a mating surface having a plurality of bumpers disposed adjacent to cooling fluid channel outlets and an axially extending ridge disposed along the radially outer edge of the mating surface. The bumpers extend circumferentially a distance H.sub.b to maintain a minimum opening G.sub.min between adjacent seal segments and extend a radial distance W.sub.b to restrict fluid from flowing axially through the clearance gap. The ridge extends radially outward to define in part a seal edge for engaging a feather seal.

Abstract: The cooling air duct for a clearance control system has spacers which abut the surface to be cooled. Critical spacing for proper cooling is obtained and is easily inspected. Ajustable supports facilitate adjustment.

Abstract: A coolable stator assembly is positioned outwardly of an array of rotor blades in a high by pass turbofan gas turbine engine as disclosed. The stator assembly includes case tied air seals positioned by rails and a shield which extends circumferentially about the rails and the rail connector section extending between the rails. Various constructions details for improving the control of clearances and circumferential temperature gradients in the rails are developed. In one particular embodiment, cooling air tubes are employed with the shield.

Abstract: An electrophotographic paper based on a flat surface bond type paper is given a photoconductive coating to one side of the paper and is cockled afterward. This "post" cockling process can be done on a suitable web roll during production of the coated electrophotographic stock, or an electrographic or electrophotographic copy sheet can be cockled or embossed after imaging, toning and fixing by a conventional electrophotographic apparatus.