The invention relates to an aircraft propulsion system (100) intended for being built into the rear of an aircraft fuselage, the propulsion system comprising at least two gas generators (102a, 102b) supplying a power turbine (104) having two counter-rotating turbine rotors (104a, 104b) for driving two fans (112a, 12b), and separate air inlets (106a, 106b) for supplying each gas generator, characterised in that it comprises an electrical drive device (140) configured to rotate at least one of the turbine rotors, at least one electrical generator (142a, 142b) configured to transform part of the energy of the flow from the gas generators into electrical power and an electric motor (146) supplied by said electrical generator and capable of rotating at least one of the turbine rotors, said electrical generator being installed on one of said gas generators, and in that said turbine rotor is capable of being rotated simultaneously by a flow from said gas generators and by the electrical drive device.

A low emission, high efficiency Gas Turbine engine operating on a combination of Natural Gas and Bio Gas as fuel, driving either a high efficiency turbo-blower or a high efficiency Turbo Pump system combined with heat recovery systems and in other embodiments is provided a generator of electricity or providing evaporate cooling from using the remaining waste heat in the exhaust gas.

A low emission, high efficiency Gas Turbine engine operating on a combination of Natural Gas and Bio Gas as fuel, driving either a high efficiency turbo-blower or a high efficiency Turbo Pump system combined with heat recovery systems and in other embodiments is provided a generator of electricity or providing evaporate cooling from using the remaining waste heat in the exhaust gas.

A hybrid electric propulsion system includes a gas turbine engine having a low speed spool and a high speed spool. The low speed spool includes a low pressure compressor and turbine, and the high speed spool includes a high pressure compressor and turbine. The hybrid electric propulsion system includes an electric generator configured to extract power from the low speed spool, an electric motor configured to augment rotational power of the high speed spool, and a controller. The controller is operable to determine a target operating condition of the low pressure compressor to achieve a compressor stability margin in the gas turbine engine, determine a current operating condition of the low pressure compressor, and control a power transfer between the electric generator of the low speed spool and the electric motor of the high speed spool to adjust the current operating condition based on the target operating condition.

A hybrid electric propulsion system includes a gas turbine engine having a low speed spool and a high speed spool. The low speed spool includes a low pressure compressor and turbine, and the high speed spool includes a high pressure compressor and turbine. The hybrid electric propulsion system includes an electric generator configured to extract power from the low speed spool, an electric motor configured to augment rotational power of the high speed spool, and a controller. The controller is operable to determine a target operating condition of the low pressure compressor to achieve a compressor stability margin in the gas turbine engine, determine a current operating condition of the low pressure compressor, and control a power transfer between the electric generator of the low speed spool and the electric motor of the high speed spool to adjust the current operating condition based on the target operating condition.

The high pressure compressor wheel of a two stage turbocharger assembly is cooled by charge air bled from the charge air flowpath downstream of the aftercooler. A wastegate may be arranged across the high pressure stage and operated by an actuator which in turn is operable by the static or dynamic pressure of the charge air in the cooling flowpath. The cooling airflow may be blocked to open the wastegate and released or resumed to close the wastegate so that cooling air is supplied only while the high pressure compressor wheel is under load.

Methods and devices for cooling systems (700) are provided that are in fluid communication with bleed air from a jet engine compressor. The cooling system can include: a first precooler (210) receiving bleed air from the jet engine compressor; a heat exchanger (730) downstream from the first precooler (210); a cooling system compressor (220) downstream from the first precooler (210), wherein the heat exchanger (730) and the cooling system compressor (220) are in separate flow paths from the first precooler (210); a cooling system precooler (230) downstream from the cooling system compressor (220); a VGT cooling system turbine (240) downstream from the cooling system precooler (230); and a discharge conduit (245) downstream from the cooling system turbine (240) and the heat exchanger (730). A bypass line (290) for bypassing the turbine can also be included.

Methods and devices for cooling systems (700) are provided that are in fluid communication with bleed air from a jet engine compressor. The cooling system can include: a first precooler (210) receiving bleed air from the jet engine compressor; a heat exchanger (730) downstream from the first precooler (210); a cooling system compressor (220) downstream from the first precooler (210), wherein the heat exchanger (730) and the cooling system compressor (220) are in separate flow paths from the first precooler (210); a cooling system precooler (230) downstream from the cooling system compressor (220); a VGT cooling system turbine (240) downstream from the cooling system precooler (230); and a discharge conduit (245) downstream from the cooling system turbine (240) and the heat exchanger (730). A bypass line (290) for bypassing the turbine can also be included.

Methods and devices for cooling systems (100, 700) are provided that are in fluid communication with bleed air from a jet engine compressor. The cooling systems include: a first precooler (210) receiving bleed air from the jet engine compressor; a heat exchanger (730) downstream from the first precooler (210); a cooling system compressor (220) downstream from the first precooler (210), wherein the heat exchanger (730) and the cooling system compressor (220) are in separate flow paths from the first precooler (210); a cooling system precooler (230) downstream from the cooling system compressor (220); a cooling system turbine (240) with variable guide vanesVGTand downstream from the cooling system precooler (230); and a discharge conduit (245) downstream from the cooling system turbine (240) and the heat exchanger (730). A bypass line (290) can also be included that bypasses the cooling system turbine (240).

Methods and devices for cooling systems (100, 700) are provided that are in fluid communication with bleed air from a jet engine compressor. The cooling systems include: a first precooler (210) receiving bleed air from the jet engine compressor; a heat exchanger (730) downstream from the first precooler (210); a cooling system compressor (220) downstream from the first precooler (210), wherein the heat exchanger (730) and the cooling system compressor (220) are in separate flow paths from the first precooler (210); a cooling system precooler (230) downstream from the cooling system compressor (220); a cooling system turbine (240) with variable guide vanesVGTand downstream from the cooling system precooler (230); and a discharge conduit (245) downstream from the cooling system turbine (240) and the heat exchanger (730). A bypass line (290) can also be included that bypasses the cooling system turbine (240).