Systems and methods for operating an aircraft engine using multiple fuel types

An aircraft propulsion system comprising:

• a combustor section including a combustor forming a first portion of a core flow path through the aircraft propulsion system;
• a heat exchanger;
• a fuel system assembly including a jet fuel system, a hydrogen fuel system, and a switching valve,
• the jet fuel system including a jet fuel metering system connected in fluid communication with the combustor and the switching valve,
• the hydrogen fuel system including a hydrogen fuel metering system and a liquid hydrogen source, the hydrogen fuel metering system connected in fluid communication between the combustor, the liquid hydrogen source and the switching valve, and
• the switching valve in fluid communication with and upstream of the heat exchanger, the switching valve configured to switch between a first circuit flow path and a second circuit flow path, the first circuit flow path extending between the jet fuel system and the heat exchanger, and the second circuit flow path extending between the hydrogen fuel system and the heat exchanger;
• and
• a control system including an engine controller connected in signal communication with the switching valve, the engine controller including a first processing system, the first processing system including a first processor connected in signal communication with a non-transitory first memory storing first instructions which, when executed by the first processor, cause the first processor to:
• operate the fuel system assembly in one of a first fuel mode or a second fuel mode;
• and
• configure the switching valve with one of the first circuit flow path for the first fuel mode or the second circuit flow path for the second fuel mode,
• the switching valve with the first circuit flow path configured to direct a jet fuel from the jet fuel system through the heat exchanger and to the combustor through the jet fuel metering system, and
• the switching valve with the second circuit flow path configured to direct a hydrogen fuel from the hydrogen fuel system through the heat exchanger and to the combustor through the hydrogen fuel metering system.

An aircraft propulsion system comprising:

• a combustor section including a combustor forming a first portion of a core flow path through the aircraft propulsion system;
• an engine oil system including a fuel-oil heat exchanger;
• a fuel system assembly including a jet fuel system, a hydrogen fuel system and a switching valve,
• the jet fuel system a low-pressure stage pump, a high-pressure stage pump, and a jet fuel metering system forming a jet fuel flow path, the jet fuel metering system connected in fluid communication with and between the high-pressure stage pump and the combustor,
• the hydrogen fuel system including a hydrogen fuel flow path, the hydrogen fuel system including a hydrogen fuel source and a hydrogen fuel metering system forming the hydrogen fuel flow path, the hydrogen fuel metering system connected in fluid communication with and between the hydrogen fuel source, the switching valve, and the combustor, and
• the switching valve configured to switch between a first circuit flow path and a second circuit flow path, the first circuit flow path extending between the jet fuel system and the fuel-oil heat exchanger, and the second circuit flow path extending between the hydrogen fuel system and the fuel-oil heat exchanger;
• and
• a control system including an engine controller connected in signal communication with the switching valve, the engine controller including a first processing system, the first processing system including a first processor connected in signal communication with a non-transitory first memory storing first instructions which, when executed by the first processor, cause the first processor to:
• operate the fuel system assembly in one of a first fuel mode or a second fuel mode;
• and
• configure the switching valve with one of a first circuit flow path for the first fuel mode or a second circuit flow path for the second fuel mode,
• the switching valve with the first circuit flow path configured to direct a jet fuel from the low-pressure stage pump, through the fuel-oil heat exchanger, and to the high-pressure stage pump along the jet fuel flow path, and
• the switching valve with the second circuit flow path configured to direct a hydrogen fuel from the hydrogen fuel metering system, through the fuel-oil heat exchanger, and to the hydrogen fuel metering system along the hydrogen fuel flow path.