Abstract: An aircraft propulsion system includes a combustor, an engine oil system, and a fuel system assembly. The engine oil system includes a fuel-oil heat exchanger. The fuel system assembly includes a jet fuel system, a hydrogen fuel system, and a switching valve. The jet fuel system and the hydrogen fuel system are connected in fluid communication with the combustor. The jet fuel system is selectively connected in fluid communication with the fuel-oil heat exchanger by the switching valve. The hydrogen fuel system is selectively connected in fluid communication with the fuel-oil heat exchanger by the switching valve. The switching valve is configurable between a first circuit flow path and a second circuit flow path. The switching valve configured in the first circuit flow path directs the jet fuel through the fuel-oil heat exchanger. The switching valve configured in the second circuit flow path directs the gaseous hydrogen fuel through the fuel-oil heat exchanger.

Abstract: An aircraft propulsion system includes a combustor, an engine oil system, and a fuel system assembly. The engine oil system includes a fuel-oil heat exchanger. The fuel system assembly includes a jet fuel system, a hydrogen fuel system and a switching valve. The jet fuel system and the hydrogen fuel system are connected in fluid communication with the combustor. The jet fuel system is further selectively connected in fluid communication with the fuel-oil heat exchanger by the switching valve. The hydrogen fuel system includes a liquid hydrogen source. The hydrogen fuel system is further selectively connected in fluid communication with the fuel-oil heat exchanger by the switching valve. The switching valve configured in a first circuit flow path directs the jet fuel through the fuel-oil heat exchanger. The switching valve configured in a second circuit flow path directs the hydrogen fuel through the fuel-oil heat exchanger.

Abstract: An aircraft propulsion system includes a combustor, an engine oil system, and a fuel system assembly. The engine oil system includes a fuel-oil heat exchanger. The fuel system assembly includes a jet fuel system, a hydrogen fuel system, and a switching valve. The jet fuel system and the hydrogen fuel system are connected in fluid communication with the combustor. The jet fuel system is selectively connected in fluid communication with the fuel-oil heat exchanger by the switching valve. The hydrogen fuel system is selectively connected in fluid communication with the fuel-oil heat exchanger by the switching valve. The switching valve is configurable between a first circuit flow path and a second circuit flow path. The switching valve configured in the first circuit flow path directs the jet fuel through the fuel-oil heat exchanger. The switching valve configured in the second circuit flow path directs the gaseous hydrogen fuel through the fuel-oil heat exchanger.

Abstract: An aircraft propulsion system includes a compressor section, a combustor section, and a fuel system assembly. The compressor section includes a plurality of inlet guide vanes, an inlet guide vane actuator (IGVA), and an IGVA servo. The IGVA is operably coupled with the plurality of inlet guide vanes. The IGVA servo is connected in fluid communication with the IGVA. The combustor section includes a combustor. The fuel system assembly includes a jet fuel system and a hydrogen fuel system. The jet fuel system is connected in fluid communication with the combustor. The hydrogen fuel system is connected in fluid communication with the combustor and the IGVA servo. The hydrogen fuel system is configured to direct the hydrogen fuel to the IGVA servo to control a position of the IGVA.

Abstract: An aircraft propulsion system includes a compressor section, a combustor section, and a fuel system assembly. The compressor section includes a plurality of inlet guide vanes, an inlet guide vane actuator (IGVA), and an IGVA servo. The IGVA is operably coupled with the plurality of inlet guide vanes. The IGVA servo is connected in fluid communication with the IGVA. The combustor section includes a combustor. The fuel system assembly includes a jet fuel system and a hydrogen fuel system. The jet fuel system is connected in fluid communication with the combustor and the IGVA servo. The hydrogen fuel system is connected in fluid communication with the combustor and the IGVA servo.

Abstract: An aircraft propulsion system includes a combustor section, an engine oil system, and a fuel system. The combustor section includes a combustor forming a first portion of a core flow path through the aircraft propulsion system. The engine oil system includes a fuel-oil heat exchanger. The fuel system assembly includes a jet fuel system and a hydrogen fuel system. The jet fuel system is connected in fluid communication with the combustor and configured to selectively direct a jet fuel to the combustor. The hydrogen fuel system is connected in fluid communication with the combustor and configured to selectively direct a hydrogen fuel to the combustor. The hydrogen fuel system is further connected in fluid communication with the fuel-oil heat exchanger.

Abstract: Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifold and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and supplying pressurized air to the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

Abstract: Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifold and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and supplying pressurized air to the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

Abstract: Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifold and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and supplying pressurized air to the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

Abstract: Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifold and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and supplying pressurized air to the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

Abstract: Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifold and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and supplying pressurized air to the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

Abstract: A thermal actuator has a bellows construction with a heat-transfer fluid (e.g. oil) located outside the bellows and a thermal expansion material (e.g. wax) located inside the interior volume of the bellows.

Abstract: Methods and systems of operating a gas turbine engine in a low-power condition are provided. In one embodiment, the method includes supplying fuel to a combustor by supplying fuel to a first fuel manifold and a second fuel manifold of the gas turbine engine. The method also includes, while supplying fuel to the combustor by supplying fuel to the first fuel manifold: stopping supplying fuel to the second fuel manifold; and supplying pressurized air to the second fuel manifold to flush fuel in the second fuel manifold into the combustor and hinder coking in the second fuel manifold and associated fuel nozzles.

Abstract: A thermal actuator has a bellows construction with a heat-transfer fluid (e.g. oil) located outside the bellows and a thermal expansion material (e.g. wax) located inside the interior volume of the bellows.