Abstract: A propulsion system for aircraft comprises fuel reservoirs for storing hydrogen and a fuel reservoir for storing a liquid hydrocarbon fuel (HC). A gas turbine engine may comprise a fuel injection unit comprising: a hydrogen pilot burner in communication with hydrogen fuel reservoirs via flow control valves. A dual fuel main burner in communication with the hydrogen fuel reservoirs via a flow control valve and in communication with the HC reservoir via a third flow control valve may also be provided. A control system may be operable to control: the flow control valves to control flow of hydrogen from the hydrogen fuel reservoirs to the hydrogen pilot burner; the flow control valve to control flow of hydrogen from the hydrogen fuel reservoirs to the dual fuel main burner; and the flow control valve to control flow of the HC from the HC reservoir to the dual fuel main burner.

Abstract: A compressor system for a turbo machine is provided. The turbo machine includes a low-pressure shaft coupled to a low-pressure turbine and a high-pressure shaft coupled to a high-pressure turbine. The high-pressure shaft and the low-pressure shaft are rotatable about a central rotational axis. The compressor system includes a fan driven by the low-pressure turbine via the low-pressure shaft, a booster compressor and a gear unit. The low-pressure shaft is coupled to a first input member of the gear unit. The high-pressure shaft is coupled to a second input member of the gear unit. An intermediate rotor is coupled to an output member of the gear unit. The intermediate rotor includes rotatable elements of the booster compressor and an electric motor-generator. The intermediate rotor is driven by the low-pressure shaft and the high-pressure shaft.