Disclosed is a turbine bypass for an engine with a driven turbocharger. During engine cold start, or periods of idle or low load engine operation, the bypass can be utilized to direct hot exhaust gasses directly to an exhaust aftertreatment. This provides higher temperatures to the exhaust aftertreatment, increasing the ability to eliminate harmful emissions such as NOx. The driven turbocharger can still provide boost to the engine through supercharging, so that engine torque and power can be maintained while the turbine bypass is in operation.

A method of raising exhaust gas temperatures of a two-cycle uniflow scavenged engine at lower loads. At lower loads, the exhaust valves are activated with a frequency that is less frequent than every engine cycle. This exhaust valve deactivation may be combined with additional engine operating strategies, such as by using fewer than all cylinders as combusting cylinders, adjusting fueling to combusting cylinders, and reducing compressor output.

An engine assembly including an internal combustion engine configured to be received in an engine compartment and a heat exchanger having a first conduit fluidly connected to a fluid circuitry of the engine and a second conduit fluidly connecting an interior of the engine compartment to its environment. The first conduit is in heat exchange relationship with the second conduit. The assembly further includes a forced air system operable in use to provide an air flow from the environment to the outlet via the second conduit of the heat exchanger and the engine compartment. The assembly further includes a selector valve configurable to selectively fluidly connect an air intake of the internal combustion engine with the interior of the engine compartment in a first valve position and with the environment in a second valve position. A method for supplying air to an internal combustion engine is also discussed.

The invention provides an internal combustion engine system (1) comprisingat least one combustor (3), anda first expander (4) arranged to receive exhaust gases from at least one of the at least one combustor (3), and to expand and extract energy from the exhaust gases, characterized in that the system comprises a second expander (5) arranged to receive exhaust gases from the first expander (4), and to expand and extract energy from the exhaust gases.

The invention is an electrical machine, comprising a stator being radial passages (102) circumferentially arranged along the stator. These radial passages (102) are delimited by radial teeth (101) and magnetic flux generators are housed in these radial passages (102). Furthermore, radial passages (102) comprise fluid circulation galleries facing the magnetic flux generators. The electrical machine comprises at least one aerodynamic appendages (85, 90), coaxial with the electrical machine, and arranged at a longitudinal end of the electrical machine. Aerodynamic appendages (85, 90) comprise a first part for guiding the fluid passing through the circulation galleries, and a second part extending radially along at least one of radial teeth (101) and having an aerodynamic profile for guiding the fluid.

A compounding drive includes an input member, an epicyclical gear arrangement connected to the input member, an output member connected to the epicyclical gear arrangement, and a hydraulic pump/motor set. The hydraulic pump/motor set connects the epicyclical gear arrangement to the output member through an overrunning clutch for unidirectional communication of mechanical rotation between the input member and the output member. Engine arrangements, aircraft, and methods of compounding internal combustion engines are also described.

A method of raising exhaust gas temperatures of a two-cycle uniflow scavenged engine at lower loads. At lower loads, the exhaust valves are activated with a frequency that is less frequent than every engine cycle. This retains exhaust within the cylinder for one or more cycles, and when the exhaust valves are again activated, the exhaust temperature will be elevated. For engines having a means for controlling intake manifold pressure, such as a compressor having variable speed or a means for bleeding off compressor output, intake manifold pressure can be reduced at low loads, which also has the effect of elevating exhaust temperatures.

A turbocharger variable speed control mechanism for a turbocharger for an engine includes a sun gear of a planetary gear set coupled to a turbocharger shaft, a planet carrier operatively connected to an engine output shaft of the engine, a brake disk coupled to and rotatable with a ring gear, and a brake actuator mechanism proximate the brake disk and mounted to a turbocharger housing. The brake actuator mechanism is selectively actuatable between a non-braking state where no braking force is applied to the brake disk so that the ring gear is free to rotate relative to the turbocharger housing, and a full braking state where a full braking force is applied to the brake disk such that the ring gear is held stationary relative to the turbocharger housing and rotation of the planet carrier is transmitted through the planetary gear set to cause rotation of the turbocharger shaft.

A hybrid propulsion system includes a heat engine configured to drive a heat engine shaft. An electric motor is configured to drive an electric motor shaft. A transmission system includes at least one gearbox. The transmission system is configured to receive rotational input power from each of the heat engine shaft and the electric motor shaft and to convert the rotation input power to output power.

An internal combustion engine system includes at least one combustor, and a first expander arranged to receive exhaust gases from at least one of the at least one combustor, and to expand and extract energy from the exhaust gases, wherein the system includes a second expander arranged to receive exhaust gases from the first expander, and to expand and extract energy from the exhaust gases.