Disclosed is an air cycle machine (ACM) having: a turbine; a compressor; a compressor shaft connected to the compressor and configured to receive rotational energy from a gearbox; and a turbine shaft connected to the turbine and configured to provide rotational energy to the gearbox; wherein the turbine shaft and the compressor shaft operate at different rotational speeds.

An aspect includes a system for pre-start motoring control for multiple engines of an aircraft. The system includes a first engine starting system of a first engine and a controller. The controller is operable to control a motoring time of the first engine starting system relative to one or more other engine starting systems of one or more other engines of the aircraft by adjusting the motoring time of the first engine starting system within a tolerance of the motoring time of the one or more other engine starting systems in a pre-start motoring sequence.

A cooling system for a turbine engine including a heat exchanger in fluid communication with a first fluid inlet stream and disposed upstream and in fluid communication with a core engine. The heat exchanger operative to cool the first fluid inlet stream. The heat exchanger including a heat exchanger inlet for input of a heat exchanging medium for exchange of heat from the first fluid inlet stream to the heat exchanging medium. The heat exchanger further including a heat exchanger outlet for discharge of a heated output stream into one of a turbine of a downstream engine, an augmentor or a combustor of the core engine. The heated output stream provides an additional flow to the downstream engine. A turbine engine including the cooling system is disclosed.

A method includes receiving a command to operate a power load of a power system at a command output power while operating the power load at a reference output power; operating a gas turbine engine of the power system in a maximum regulator mode to increase a power generation of the gas turbine engine when the command output power is greater than the reference output power or in a minimum regulator mode to decrease the power generation of the gas turbine engine when the command output power is less than the reference output power; and coordinating an electric machine power draw from the gas turbine engine with a change in power generation of the gas turbine engine to maintain a rotational speed parameter of the gas turbine engine substantially constant while operating the gas turbine engine in the maximum regulator mode or in the minimum regulator mode.

A drive architecture comprises a rotor and a gearbox for driving the rotor. A pair of input gears provides rotational drive to the gearbox. A first recuperative cycle engine drives one of the pair of gears and a second engine drives the other of the pair of gears. The first recuperative cycle engine and the second engine are both gas turbine engines. A power takeoff from a drive shaft of the second engine supplies rotational drive to drive at least one component in the first recuperative cycle drive.

A hybrid electric gas turbine engine includes a fan section, a turbine section, a first gas generating core, and a generator assembly. The fan section has a fan. The turbine section has a turbine drivably connected to the fan through a main shaft that extends along a central longitudinal axis. The first gas generating core extends along a first axis that is radially offset from the central longitudinal axis. The generator assembly is drivably connected to the main shaft through a gear assembly.

An aspect includes a system for pre-start motoring synchronization for multiple engines of an aircraft. The system includes a first engine starting system of a first engine and a controller. The controller is operable to synchronize a motoring time of the first engine starting system with one or more other engine starting systems of one or more other engines of the aircraft by extending the motoring time of the first engine starting system to match, within a synchronization tolerance, the motoring time of the one or more other engine starting systems in a pre-start motoring sequence.

A cooling system for a turbine engine including a heat exchanger in fluid communication with a first fluid inlet stream and disposed upstream and in fluid communication with a core engine. The heat exchanger operative to cool the first fluid inlet stream. The heat exchanger including a heat exchanger inlet for input of a heat exchanging medium for exchange of heat from the first fluid inlet stream to the heat exchanging medium. The heat exchanger further including a heat exchanger outlet for discharge of a heated output stream into one of a turbine of a downstream engine, an augmentor or a combustor of the core engine. The heated output stream provides an additional flow to the downstream engine. A turbine engine including the cooling system is disclosed.

The Compressed Gas and Recycled Liquid Turbine Power System (CGRLTPS) generates rotational energy by converting energy stored within compressed gas into rotational energy and can convert that rotational energy into electricity.

The turboshaft engine for a rotorcraft includes a low pressure spool having a low pressure compressor and a low pressure turbine section, and a high pressure spool having a high pressure compressor and a high pressure turbine section. The spools are independently rotatable relative to one another. The low pressure compressor section includes a mixed flow rotor. A set of variable guide vanes (VGVs) are disposed upstream of each of the low pressure and high pressure compressors, the VGVs being configured to be independently operable relative to one another.