A method of operating a gas turbine engine includes commanding an acceleration of the gas turbine engine and moving a variable pitch high pressure compressor vane toward an open position thereby reducing an acceleration rate of a high pressure turbine rotor thereby reducing a change in a clearance gap between the high pressure turbine rotor and a blade outer airseal. An active clearance control system of a gas turbine engine includes an engine control system configured to command an acceleration of the gas turbine engine and move a variable pitch high pressure compressor vane toward an open position thereby slowing an acceleration rate of a high pressure turbine rotor thereby reducing a change in a clearance gap between the high pressure turbine rotor and a blade outer airseal located radially outboard of the high pressure turbine rotor.

A method for is provided. The method can include receiving data characterizing a first measurement image having a first state and a first set of three-dimensional coordinate data corresponding to the first measurement image. The first measurement image can include two-dimensional image data. The method can also include receiving data characterizing at least one geometric dimension determined for the first measurement image. The method can further include receiving data characterizing a second measurement image having a second state and a second set of three-dimensional coordinate data corresponding to the second measurement image. The method can also include applying the first state of the first measurement image to the second measurement image. The method can further include displaying at least one second geometric dimension determined using the second set of three-dimensional coordinate data. Related systems performing the method are also provided.

An assembly for a turbine of a turbine engine, including a casing and an annular duct surrounding the casing, which can be connected to a device for supplying cooling air, and having a radially inner annular wall provided with openings arranged opposite the casing in order to cool same by the impact of cooling-air jets. The casing has a plurality of axial grooves including first grooves and second grooves arranged in alternation, and the openings are distributed in a plurality of annular rows in which any pair of consecutive annular rows is such that the openings of one of the annular rows of the pair are centered relative to the first grooves while the openings of the other annular row of the pair are centered relative to the second grooves.

An assembly for a turbine of a turbine engine, including a casing and an annular duct surrounding the casing, which can be connected to a device for supplying cooling air, and having a radially inner annular wall provided with openings arranged opposite the casing in order to cool same by the impact of cooling-air jets. The casing has a plurality of axial grooves including first grooves and second grooves arranged in alternation, and the openings are distributed in a plurality of annular rows in which any pair of consecutive annular rows is such that the openings of one of the annular rows of the pair are centered relative to the first grooves while the openings of the other annular row of the pair are centered relative to the second grooves.

Systems and methods are disclosed herein for passively managing cooling air in a gas turbine engine. A cooling air supply line may supply cooling air to a component in the gas turbine engine. A metering coupon may have a negative coefficient of thermal expansion. The metering coupon may allow more airflow through the metering coupon and through the component in response to an increase in temperature.

Systems and methods are disclosed herein for passively managing cooling air in a gas turbine engine. A cooling air supply line may supply cooling air to a component in the gas turbine engine. A metering coupon may have a negative coefficient of thermal expansion. The metering coupon may allow more airflow through the metering coupon and through the component in response to an increase in temperature.

A system for controlling blade tip clearances in a gas turbine engine may comprise an active clearance control system and a controller in operable communication with the active clearance control system. The controller may be configured to identify a cruise condition, reduce a thrust limit of the gas turbine engine to a de-rated maximum climb thrust, determine a first target tip clearance based on the de-rated maximum climb thrust, and send a command signal correlating to the first target tip clearance to the active clearance control system.

A gas turbine engine includes a blade track, a support assembly, and a seal system. The blade track is arranged around a central axis of the gas turbine engine to direct gasses through the gas turbine engine. The support assembly is arranged around the blade track to support the blade track relative to the central axis. The seal system is configured to block fluid communication between pressurized cavities formed in the support assembly.

A shroud assembly including a shroud support and an annular shroud is provided. The shroud assembly includes one or more pins for securing the annular shroud to the shroud support. The pins having a block capable of translating radially to allowing the shroud to expand and contract in the radial direction. A gas turbine engine having a compressor section, a combustion section, a turbine section and a shroud assembly is also provided. The shroud assembly includes one or more pins for securing the continuous shroud to the shroud support. The pins having a block capable of translating radially to allowing the shroud to expand and contract in the radial direction. Methods for assembling a shroud assembly structure in a gas turbine engine are also provided.

A thrust demand signal is provided to a processor of a gas turbine engine and is modified, according to growth time constants of a rotor and/or a casing of the engine, in order to control the rotational speed or the rate of change of rotational speed of the engine so as to prevent contact between the rotor and the casing.