HYBRID ELECTRIC POWER FOR TURBINE ENGINES HAVING HYDROGEN FUEL SYSTEMS

An aircraft propulsion systems (400) has an aircraft systems (404) including at least one hydrogen tank (432) and an aircraft-systems heat exchanger (458) and engine systems (402) includes at least a main engine core, a high pressure pump (416), a hydrogen-air heat exchanger (424), and a turbo expander (420). The main engine core includes a compressor section, a combustor section having a burner (410), and a turbine section arranged along an engine shaft. Hydrogen is supplied from the at least one hydrogen tank (432) through a hydrogen flow path (444), passing through the aircraft-systems heat exchanger (458), the high pressure pump (416), the hydrogen-air heat exchanger (424), and the turbo expander (420), prior to being injected into the burner (410) for combustion. The turbo expander (420) is configured to impart power to the engine shaft.