In accordance with at least one aspect of this disclosure, there is provided a heat exchange system. The heat exchange system includes a first heat exchanger and a second heat exchanger. The first heat exchanger includes an engine fluid conduit fluidly connecting an engine fluid inlet to an engine fluid outlet. A first internal buffer fluid conduit fluidly connects a first buffer fluid inlet to a first buffer fluid outlet where the engine fluid conduit is in fluid isolation from the first internal buffer fluid conduit but is in thermal communication with the first internal buffer fluid conduit for heat exchange between the engine fluid and the buffer fluid.

An engine assembly includes a combustor wall with a first skin, a second skin, a core and a sound attenuation passage. The first skin forms a peripheral boundary of a combustion volume on a first side of the combustor wall. The second skin forms a peripheral boundary of a plenum on a second side of the combustor wall. The core includes a plurality of resonator elements between the first skin and the second skin. A first resonator element includes a first base and a plurality of first protrusions projecting out from the first base. Each first protrusion includes a first bore fluidly coupled with a first cavity within the first base. The sound attenuation passage extends within the core and is fluidly coupled with the combustion volume through an attenuation passage aperture in the first skin. The sound attenuation passage is fluidly decoupled from the plenum by the second skin.

An engine assembly includes a combustor wall with a first skin, a second skin, a core and a sound attenuation passage. The first skin forms a peripheral boundary of a combustion volume on a first side of the combustor wall. The second skin forms a peripheral boundary of a plenum on a second side of the combustor wall. The core includes a plurality of resonator elements between the first skin and the second skin. A first resonator element includes a first base and a plurality of first protrusions projecting out from the first base. Each first protrusion includes a first bore fluidly coupled with a first cavity within the first base. The sound attenuation passage extends within the core and is fluidly coupled with the combustion volume through an attenuation passage aperture in the first skin. The sound attenuation passage is fluidly decoupled from the plenum by the second skin.

A method of producing compressed air for use onboard an aircraft includes receiving compressor discharge air into an air channel of a fuel injector. The method also includes cooling the compressor discharge air within the air channel by heat exchange with fuel flowing in the fuel injector, and issuing cooled air from the internal air channel out of an engine case as a source of compressed air.

A method of producing compressed air for use onboard an aircraft includes receiving compressor discharge air into an air channel of a fuel injector. The method also includes cooling the compressor discharge air within the air channel by heat exchange with fuel flowing in the fuel injector, and issuing cooled air from the internal air channel out of an engine case as a source of compressed air.

A turbine engine system includes aircraft systems including at least one hydrogen fuel tank, engine systems comprising a compressor section, a combustor section having a burner, and a turbine section, and a hydrogen fuel flow supply line configured to supply hydrogen fuel from the at least one hydrogen fuel tank into the burner for combustion. The turbine engine system has a bypass ratio between 5 to 20.

A system and method of increasing the temperature of oil that is used to anti-ice a gas turbine propulsion engine includes supplying oil from an oil supply system to an anti-ice oil circulation system that is disposed within the front frame of the gas turbine propulsion engine, and selectively injecting compressed air from the gas turbine propulsion engine into the oil supply system.

A system and method of increasing the temperature of oil that is used to anti-ice a gas turbine propulsion engine includes supplying oil from an oil supply system to an anti-ice oil circulation system that is disposed within the front frame of the gas turbine propulsion engine, and selectively injecting compressed air from the gas turbine propulsion engine into the oil supply system.

A gas turbine engine having a fluid transfer connection is provided. The gas turbine engine includes a first component configured to channel a flow of air from a portion of the gas turbine engine; a second component configured to receive the flow of air from the first component, wherein the first component and the second component are movable relative to one another; a sleeve portion disposed between the first component and the second component; and a spoolie device disposed within the sleeve portion, the spoolie device having elliptical shaped opposing ends, wherein the spoolie device bridges the first component and the second component to channel the flow of air from the first component to the second component.

A gas turbine engine having a fluid transfer connection is provided. The gas turbine engine includes a first component configured to channel a flow of air from a portion of the gas turbine engine; a second component configured to receive the flow of air from the first component, wherein the first component and the second component are movable relative to one another; a sleeve portion disposed between the first component and the second component; and a spoolie device disposed within the sleeve portion, the spoolie device having elliptical shaped opposing ends, wherein the spoolie device bridges the first component and the second component to channel the flow of air from the first component to the second component.