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.

The present disclosure is directed to an impingement insert for a gas turbine engine. The impingement insert includes an insert wall having an inner surface and an outer surface spaced apart from the inner surface. A nozzle extends outwardly from the outer surface of the insert wall. The nozzle includes an outer surface and a circumferential surface. The insert wall and the nozzle collectively define a cooling passage extending from the inner surface of the insert wall to the outer surface of the nozzle. The cooling passage includes an inlet portion, a throat portion, a converging portion extending from the inlet portion to the throat portion, an outlet portion, and a diverging portion extending from the throat portion to the outlet portion. The cooling passage further includes a cross-sectional shape having a semicircular portion and a non-circular portion.

A system includes a turbomachine rotor having a shaft and turbomachine blades coupled to the shaft. The system also includes a turbomachine stator having a shroud surrounding the turbomachine blades of the turbomachine rotor. Further, the system includes a cooling channel having at least a first portion of the cooling channel extending upstream of a final stage of a compressor of the system, where the cooling channel is configured to receive cooled compressed air from the compressor and direct the cooled compressed air adjacent to the turbomachine rotor to reduce thermal expansion and/or axial displacement of the turbomachine rotor.

A system includes a turbomachine rotor having a shaft and turbomachine blades coupled to the shaft. The system also includes a turbomachine stator having a shroud surrounding the turbomachine blades of the turbomachine rotor. Further, the system includes a cooling channel having at least a first portion of the cooling channel extending upstream of a final stage of a compressor of the system, where the cooling channel is configured to receive cooled compressed air from the compressor and direct the cooled compressed air adjacent to the turbomachine rotor to reduce thermal expansion and/or axial displacement of the turbomachine rotor.

Various embodiments include a heat transfer device, a turbomachine casing and a related storage medium. In some cases, the device includes: a body having an outer surface and an inner cavity within the outer surface; at least one aperture extending through the body, the at least one aperture positioned to direct fluid from the inner cavity through the body to the outer surface; a first lip proximate a first end of the body, and a second lip proximate a second end of the body, the first lip and the second lip each extending radially outward from the outer surface relative to a direction of flow of the fluid through the inner cavity; and a plug coupled with the body, the plug for obstructing an end of the inner cavity, the plug positioned to redirect flow of the fluid from a first direction to a second, distinct direction.

A turbomachine includes a compressor portion, and a turbine portion operatively connected to the compressor portion. The turbine portion includes a turbine casing. A combustor assembly, including at least one combustor, fluidically connects the compressor portion and the turbine portion. At least one of the compressor portion, turbine portion and combustor assembly includes a sensing cavity. A passive clearance control system is operatively arranged in the turbomachine. The passive clearance control system includes at least one passive flow modulating device mounted in the sensing cavity, and at least one cooling channel extending from the sensing cavity through the casing. The at least one passive flow modulating device selectively passes the fluid from the sensing cavity through the at least one cooling channel to adjust a clearance between stators and rotating airfoils in the turbine portion.

A passive transpirational flow acoustic liner assembly for a gas turbine engine includes a guide vane assembly and a conduit configured to deliver airflow received from the guide vane. The guide vane assembly includes an airfoil having a transpirational flow acoustic liner. The acoustic liner includes a face sheet defining a portion of an outer surface of the airfoil and having a plurality of first apertures, a segmented member coupled to the face sheet and having a plurality of chambers in fluid communication with the outer surface via the plurality of first apertures, a backing sheet having a plurality of apertures and being coupled to the segmented member such that the segmented member is positioned between the face sheet and the backing sheet, and a plenum coupled to the backing sheet opposite the segmented member and fluidly connected to the conduit.

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 system for controlling the clearance distance between an impeller blade tip of a centrifugal compressor and a radially inner surface of an impeller shroud in a turbine engine. The system comprises a thermal driver coupled between the impeller shroud and engine casing by hinged linkages. The thermal driver includes an annular ring and annular seal which together define thermal driver cavity. Relatively warm or relatively cool air supplied to the thermal driver cavity cause expansion and contraction, respectively, of the annular ring which is translated by linkages into axially forward and aft motion, respectively.