Aircraft power unit with elective mechanical coupling

The method of achieving efficient high and low altitude operation in an aircraft power unit comprising the steps of:

• supporting inlet port compressor fan and outlet port turbine fan elements of said aircraft power unit on clutch-coupleable rotationally segregated inlet and outlet shafts in said power unit;
• coupling an energizing flow of hot gasses from an oxidizable fuel burning combustion chamber apparatus to said outlet port turbine fan elements during high and low altitude operation of said aircraft power unit;
• selecting compressor fan pressurized ambient air as an oxidizing element for said oxidizable fuel during low altitude dense air operation of said aircraft power unit and choosing a stored supply of oxidant material for oxidizing element use during high altitude thin air operation of said aircraft power unit;
• said selecting step including clutch coupling of said inlet and outlet shafts, with said turbine fan energizing said compressor fan and supplying said ambient air oxidizing material to said combustion chamber apparatus during said low altitude dense air operation of said aircraft power unit and
• said selecting step also including clutch decoupling of said inlet and outlet shafts, and an attending de-energizing of said compressor fan during said high altitude thin air operation of said aircraft power unit;
• generating an electrical energy output of said aircraft power unit from turbine fan derived rotational mechanical energy received via said outlet shaft.

An efficient, high altitude turbine-fan energized aircraft auxiliary power and aircraft emergency power generating integrated power unit comprising the combination of:

• hot gas energizable turbine fan apparatus having a first rotatable shaft member mechanical energy output;
• a first generator/motor reluctance electrical machine mechanically coupled with said first rotatable shaft member;
• ambient inlet air compressor fan apparatus having a second rotatable shaft member mechanical energy input and a pressurized air flow output;
• a second generator/motor reluctance electrical machine mechanically coupled with said second rotatable shaft member;
• hot gas generator means including oxidizable fuel and oxidant combining combustion chamber apparatus disposed in hot gas-flow communication with said turbine fan apparatus;
• a host aircraft carried stored supply of oxidant element;
• oxidant determining means for selecting said compressor fan pressurized air flow as an oxidizing element for said oxidizable fuel during lower altitude dense air operation of said integrated power unit and said host aircraft carried stored supply of oxidizing element for said oxidizable fuel during higher altitude rarefied air operation of said integrated power unit;
• an electrically energizable electromechanical clutch member having mechanical energy input and output members connecting with said first and second rotatable shaft members respectively;
• electrical control circuit means interconnected with said electromechanical clutch member, said first and second generator/motor reluctance electrical machines, first and second shaft rotational sensors, a source of power unit start-up electrical energy, power unit load apparatus, said oxidant determining means and host aircraft altitude sensing means, for:
• mechanically joining said first and second rotatable shaft members via said electromechanical clutch member during low altitude zero shaft revolution startup and running of said power unit,
• mechanically segregating said shaft members thereby de-energizing said compressor fan apparatus and said second shaft member by said electromechanical clutch member,
• enabling a flow of said aircraft stored oxidizing element during compressor fan denergized high altitude operation of said power unit,
• coupling said second shaft member with said first shaft member via a flow of electrical energy in said generator/motor reluctance machines prior to a rotating first shaft to quiescent second shaft electromechanical clutch connection thereof,
• connecting said first and second generator/motor reluctance machines in electrical parallel and in electrical energizing relationship with said power unit load apparatus during said mechanically joined low altitude operation of said power unit, and
• connecting said first generator/motor reluctance machine in electrical energizing relationship with said power unit load apparatus during high altitude operation of said power unit.