Abstract: A method of stripping coating from a portion of a coated surface of a component. The method includes fastening a mask sheet to the component over a region adjacent the portion of the coated surface. The mask sheet has a contour generally corresponding to a contour of the surface of the component. A high pressure fluid jet is sprayed from a spray head toward the portion of the coated surface after the mask sheet is fastened to the component to strip the coating from the portion of the surface. After the coating is stripped from the portion of the surface, the mask sheet is removed from the component.

Abstract: An annular gas turbine engine combustor liner has a single piece annular shell circumscribed about a first axis of revolution. The shell has a hot side and a cold side, an annular dilution hole section, and a plurality of asymmetrical cylindrical dilution holes extending through the section. Pockets are circumferentially interdigitated between the dilution holes and extend into the shell from the cold side such that the pockets form dilution hole bosses between the pockets through which the dilution holes extend. Each of the dilution holes is circumscribed about a second axis of revolution which is not parallel to the first axis of revolution. The liner may further include forward and aft annular cooling nuggets located forward and aft of the dilution hole section and having annular film cooling slots which are open in the axially aftwardly direction.

Abstract: A combustor for a gas turbine engine includes a plurality of igniter tubes that facilitate reducing temperature gradients within the combustor in a cost effective and reliable manner. The combustor includes an annular outer liner that includes a plurality of openings sized to receive igniter tubes. Each igniter tube maintains an alignment of each igniter received therein, and includes an air impingement device that extends radially outward from the igniter tube. During operation, airflow contacting the air impingement device is channeled radially inward for impingement cooling of the igniter tubes and the combustor outer liner.

Abstract: A method of adjusting airflow through a plurality of cooling holes by depositing a thermal barrier coating on an exterior surface and/or an interior surface of the component by a physical vapor deposition process. The cooling holes are not masked. Thus, a portion of the thermal barrier coating partially obstructs airflow through the cooling holes and reduces airflow through the cooling holes. A predetermined pressure drop is developed across the cooling holes and airflow through the cooling holes is measured. The measured airflow is compared to a preselected range of desired cooling hole airflows and the steps of depositing the thermal barrier coating, developing the predetermined pressure drop, calculating airflow and comparing the measured airflow to the preselected range are repeated until the measured airflow is within the preselected range of desired cooling hole airflows.

Abstract: A method of repairing an annular transpiration cooled liner for a combustion chamber of a gas turbine engine. An annular portion of the liner including a damaged region is removed from between an upstream section and a downstream section of the liner. Sheet metal is formed into an annular replacement section having at least one axial seam extending between an upstream end and a downstream end of the replacement section. The replacement section is sized and shaped similarly to the removed annular portion of the liner. The upstream end of the formed annular section is joined to the upstream section of the liner and the downstream end of the formed annular section is joined to the downstream section of the liner.

Abstract: An article comprising a substrate and an outer metallic layer, such as a coating, is provided with augmented heat transfer from the substrate through the combination of a layer thickness of about 0.003″ to about 0.017″, a layer surface roughness of at least about 500 micro inches Ra, a layer tensile bond strength of at least about 5 ksi, and a heat transfer augmentation of at least about 1.1. A method of making the article uses an electric arc wire thermal spray process in which the atomizing gas pressure is maintained within the range of about 20-80 psi.

Abstract: A combustion apparatus for a gas turbine engine including a combustor structure having at least one combustion chamber, a dual cone fuel nozzle for injecting both fuel and water to the combustion chamber, and a swirl cup package upstream of and adjacent to the combustion chamber. The swirl cup package further includes a swirler and a venturi extending between the nozzle and the combustion chamber for mixing the fuel and water with air. The venturi is configured to have a non-uniform thickness from an upstream end to a downstream end resulting in a cross-sectional area which provides a heat transfer conduction path that reduces axial stresses imposed on the venturi when water impinges on an upstream portion of the venturi.

Abstract: A method of applying thermal barrier coating systems to a metal piece having a cooling hole extending along a central axis through the piece from a first surface of the piece to a second surface opposite the first surface. The method includes spraying a bond coat and a thermal barrier coating on the first surface at an angle and to a thickness to prevent the bond coat and thermal barrier coating from entirely filling the hole. The method also includes spraying a high pressure fluid jet from an elongate nozzle assembly having an orifice configured to direct the jet laterally away from the nozzle assembly toward the hole and in a direction generally parallel to the central axis of the hole.

Abstract: An article comprising a substrate and an outer metallic layer, such as a coating, is provided with augmented heat transfer from the substrate through the combination of a layer thickness of about 0.003″ to about 0.017″, a layer surface roughness of at least about 500 micro inches Ra, a layer tensile bond strength of at least about 5 ksi, and a heat transfer augmentation of at least about 1.1. A method of making the article uses an electric arc wire thermal spray process in which the atomizing gas pressure is maintained within the range of about 20-80 psi.

Abstract: A method of applying thermal barrier coating systems to a metal piece having a cooling hole extending along a central axis through the piece from a first surface of the piece to a second surface of the piece opposite the first surface. The method includes spraying a bond coat on the first surface of the piece and spraying a thermal barrier coating on the bond coat. Further, the method includes spraying a high pressure fluid jet from a nozzle toward the hole and in a direction generally parallel to the central axis of the hole. The fluid jet is substantially free of solid particulate thereby permitting the jet to remove the bond coat and the thermal barrier coating from the hole without removing metal from the piece.

Abstract: A method for determining the appropriate hole parameters to achieve the desired airflow in a swirler with as-cast air jet holes includes the steps of determining the desired airflow through the holes and selecting a hole angle for the holes. Next, the ratio of the hole exit area to the hole inlet area is calculated based on the desired airflow and the selected hole angle using a regression equation. Then a value is determined for either of the hole exit area or the hole inlet area, and the other area is calculated from the known ratio. Once the hole angle, hole exit area and hole inlet area have been determined, then a swirler can be cast with as-cast holes using these hole parameters.

Abstract: A one-piece cowl for use in assembled relationship with a combustor of a gas turbine engine, the cowl being of a generally annular configuration defining a central cowl axis and being axially elongated and aerodynamically contoured relative to the central cowl axis. The one-piece cowl includes an inner annular portion, an outer annular portion, and a plurality of circumferentially spaced radial ligaments connecting the inner and outer annular portions so as to form a corresponding number of openings through a middle portion of the cowl. Each radial ligament has a designated area which enables the radial ligaments to sustain the stress levels imposed on the cowl to prevent high cycle fatigue. Each opening also has a designated area which enables insertion of fuel nozzles therein without adversely affecting air flow therethrough. The designated area for the radial ligaments is a function of the designated area for the openings and a ratio of such areas falls within a specified range.

Abstract: A method of preventing water erosion and hot corrosion in a combustor of a gas turbine engine, wherein water is injected into said combustor for NOx abatement, which involves the step of applying a dense vertically cracked thermal barrier coating to certain components thereof The dense vertically cracked thermal barrier coating has a porosity of less than approximately 8% and a tensile strength in the range of approximately 4-7 ksi. The dense vertically cracked thermal barrier coating is applied to such combustor components so as to produce a segmented ceramic structure having macrocracks formed therein which are oriented substantially perpendicular to an interface of the combustor component and the segmented ceramic structure.

Abstract: A thermal barrier coating is provided which is adapted to be formed on an article subjected to a hostile thermal environment while subjected to thermally, mechanically and/or dynamically-induced stresses, such as a component of a gas turbine engine. The thermal barrier coating is composed of a bond layer that tenaciously adheres an insulative ceramic layer to the article. The bond layer is formed of a metallic oxidation-resistant material, and has an average surface roughness R.sub.a of at least about 7.5 micrometers, while the ceramic layer is characterized by being segmented by at least two sets of grooves. The grooves have substantially uniform widths of about 100 to about 500 micrometers, with adjacent grooves of each set being spaced about 10 to about 250 millimeters apart.

Abstract: A thermal barrier coating is provided which is adapted to be formed on an article subjected to a hostile thermal environment while subjected to thermally, mechanically and/or dynamically-induced stresses, such as a component of a gas turbine engine. The thermal barrier coating is composed of a bond layer that tenaciously adheres an insulative ceramic layer to the article. The bond layer is formed of a metallic oxidation-resistant material, and has an average surface roughness R.sub.a of at least about 7.5 micrometers, while the ceramic layer is characterized by being segmented by at least two sets of grooves. The grooves have substantially uniform widths of about 100 to about 500 micrometers, with adjacent grooves of each set being spaced about 10 to about 250 millimeters apart.