A system for starting a gas turbine engine of an aircraft is provided. The system includes a pneumatic starter motor, a discrete starter valve switchable between an on-state and an off-state, and a controller operable to perform a starting sequence for the gas turbine engine. The starting sequence includes alternating on and off commands to an electromechanical device coupled to the discrete starter valve to achieve a partially open position of the discrete starter valve to control a flow from a starter air supply to the pneumatic starter motor to drive rotation of a starting spool of the gas turbine engine below an engine idle speed.

An engine starting system for a gas turbine engine is provided. The engine starting system comprising: a gas turbine engine including rotational components comprising an engine compressor, an engine turbine, and a rotor shaft operably connecting the engine turbine to the engine compressor, wherein each rotational component is configured to rotate when any one of the rotational components is rotated; a permanent magnet alternator operably connected to at least one of the rotational components, the permanent magnet alternator being configured to rotate the rotational components; and a motor controller in electronic communication with the permanent magnet alternator, the motor controller being configured to command the permanent magnet alternator to rotate the rotational components at a selected angular velocity for a selected period of time.

An engine starting system for a gas turbine engine is provided, the engine starting system comprising: a gas turbine engine including rotational components comprising an engine compressor, an engine turbine, and a rotor shaft operably connecting the engine turbine to the engine compressor, wherein each rotational component is configured to rotate when any one of the rotational components is rotated; an electro-pneumatic starter operably connected to at least one of the rotational components, the electro-pneumatic starter being configured to rotate the rotational components; an electric drive motor operably connected to the electro-pneumatic starter, the electric drive motor being configured to rotate the rotational components through the electro-pneumatic starter; and a motor controller in electronic communication with the electric drive motor, the motor controller being configured to command the electric drive motor to rotate the rotational components at a selected angular velocity for a selected period of time.

An engine starting system for a gas turbine engine is provided, the engine starting system comprising: a gas turbine engine including rotational components comprising an engine compressor, an engine turbine, and a rotor shaft operably connecting the engine turbine to the engine compressor, wherein each rotational component is configured to rotate when any one of the rotational components is rotated; an electro-pneumatic starter operably connected to at least one of the rotational components, the electro-pneumatic starter being configured to rotate the rotational components; an electric drive motor operably connected to the electro-pneumatic starter, the electric drive motor being configured to rotate the rotational components through the electro-pneumatic starter; and a motor controller in electronic communication with the electric drive motor, the motor controller being configured to command the electric drive motor to rotate the rotational components at a selected angular velocity for a selected period of time.

A system for bleeding air from a core flow path of a gas turbine engine is disclosed. In various embodiments, the system includes a bleed valve having a bleed valve inlet configured to receive a bleed air from a first access point to the core flow path and a bleed valve outlet; and an air motor having a first air motor inlet configured to receive the bleed air from the bleed valve outlet and a first air motor outlet configured to exhaust the bleed air, the air motor configured to pump the bleed air from the core flow path of the gas turbine engine.

Bleed air systems for use with aircraft and related methods are disclosed. An example apparatus includes a compressor having a compressor inlet, a compressor outlet, and a first drive shaft. The compressor outlet is to be fluidly coupled to a system of an aircraft that receives pressurized air, and the compressor inlet is to receive bleed air from a low-pressure compressor of an engine of the aircraft. The example apparatus includes a gearbox operatively coupled to the first drive shaft to drive the compressor. The gearbox is to be operatively coupled to and powered by a second drive shaft extending from the engine. The example apparatus also includes a clutch disposed between the first drive shaft and the gearbox to selectively disconnect the first drive shaft from the gearbox.

Bleed air systems for use with aircraft and related methods are disclosed. An example apparatus includes a compressor having a compressor inlet, a compressor outlet, and a first drive shaft. The compressor outlet is to be fluidly coupled to a system of an aircraft that receives pressurized air, and the compressor inlet is to receive bleed air from a low-pressure compressor of an engine of the aircraft. The example apparatus includes a gearbox operatively coupled to the first drive shaft to drive the compressor. The gearbox is to be operatively coupled to and powered by a second drive shaft extending from the engine. The example apparatus also includes a clutch disposed between the first drive shaft and the gearbox to selectively disconnect the first drive shaft from the gearbox.

A solar power generating system for generating electricity and providing heat includes; at least one generator for generating the electricity; a heating element for heating a heat transfer fluid; a turbocharger having at least one turbocharger turbine and at least one turbocharger compressor, wherein the at least one turbocharger compressor is adapted to receive and pressurize the heat transfer fluid, and the at least one turbocharger turbine is coupled to the at least one turbocharger compressor, wherein the at least one turbocharger compressor receiving and expanding a heated compressed heat transfer fluid coming from the heating element to drive the at least one turbocharger compressor and; a control unit configured to control the solar power generating system by comparing thermophysical properties obtained from more than one sensors placed in the solar power generating system with predetermined data in the control unit.

A solar power generating system for generating electricity and providing heat includes; at least one generator for generating the electricity; a heating element for heating a heat transfer fluid; a turbocharger having at least one turbocharger turbine and at least one turbocharger compressor, wherein the at least one turbocharger compressor is adapted to receive and pressurize the heat transfer fluid, and the at least one turbocharger turbine is coupled to the at least one turbocharger compressor, wherein the at least one turbocharger compressor receiving and expanding a heated compressed heat transfer fluid coming from the heating element to drive the at least one turbocharger compressor and; a control unit configured to control the solar power generating system by comparing thermophysical properties obtained from more than one sensors placed in the solar power generating system with predetermined data in the control unit.

An aircraft turbomachine includes a lubricating circuit notably including a reservoir of lubricating fluid, a pump drawing lubricating fluid from the reservoir to inject it toward several components of the turbomachine, and an intake pipe connecting the reservoir to an intake orifice of the pump, the turbomachine further including a pneumatic starting circuit including a starting tube through which there circulates a flow of compressed air intended to supply a pneumatic starter of the turbomachine, wherein it includes a pneumatic line extending from the starting tube as far as the reservoir so as to supply the reservoir with compressed air so as to cause the lubricating fluid to circulate through the intake pipe towards the pump.