Engines, systems, devices, software, and methods of the present invention provide increased fuel efficiency and emission performance. The engine may include a magnesium alloy cast engine block cast as a mono-block with or without a ceramic inner core and including one or more cylinders designed to provide compression ratio of 10:1 to 14:1. Each cylinder may include one or more laser igniters, one or more supercritical fuel injectors configured to inject the fuel near or in a supercritical state, and carbon dioxide, which may be in the form of engine exhaust gas. The fuel may be diesel, gasoline, or other suitable hydrocarbons that may be cracked into smaller molecules prior to be injected into the cylinder.

Engines, systems, devices, software, and methods of the present invention provide increased fuel efficiency and emission performance. The engine may include a magnesium alloy cast engine block cast as a mono-block with or without a ceramic inner core and including one or more cylinders designed to provide compression ratio of 10:1 to 14:1. Each cylinder may include one or more laser igniters, one or more supercritical fuel injectors configured to inject the fuel near or in a supercritical state, and carbon dioxide, which may be in the form of engine exhaust gas. The fuel may be diesel, gasoline, or other suitable hydrocarbons that may be cracked into smaller molecules prior to be injected into the cylinder.

A heat exchanger for an engine is disclosed. The heat exchanger includes a vortex tube and a gas return path. Expansion media tubes, which have a working fluid therein, are located between the vortex tube and the gas return path. Hot gases in the vortex tube, along with warm gases in the return path, heat the working fluid. In one embodiment, the working fluid is delivered to a cylinder in which it expands, so as to move a piston. In one embodiment, the working fluid is fuel. In one embodiment, after the working fluid expands in the cylinder, it is recovered and burned in a combustion chamber, which is in fluid communication with the vortex tube. In one embodiment, the working fluid is water.

A heat exchanger for an engine is disclosed. The heat exchanger includes a vortex tube and a gas return path. Expansion media tubes, which have a working fluid therein, are located between the vortex tube and the gas return path. Hot gases in the vortex tube, along with warm gases in the return path, heat the working fluid. In one embodiment, the working fluid is delivered to a cylinder in which it expands, so as to move a piston. In one embodiment, the working fluid is fuel. In one embodiment, after the working fluid expands in the cylinder, it is recovered and burned in a combustion chamber, which is in fluid communication with the vortex tube. In one embodiment, the working fluid is water.

A heat exchanger for an engine is disclosed. The heat exchanger includes a vortex tube and a gas return path. Expansion media tubes, which have a working fluid therein, are located between the vortex tube and the gas return path. Hot gases in the vortex tube, along with warm gases in the return path, heat the working fluid. In one embodiment, the working fluid is delivered to a cylinder in which it expands, so as to move a piston. In one embodiment, the working fluid is fuel. In one embodiment, after the working fluid expands in the cylinder, it is recovered and burned in a combustion chamber, which is in fluid communication with the vortex tube. In one embodiment, the working fluid is water.

A heat exchanger for an engine is disclosed. The heat exchanger includes a vortex tube and a gas return path. Expansion media tubes, which have a working fluid therein, are located between the vortex tube and the gas return path. Hot gases in the vortex tube, along with warm gases in the return path, heat the working fluid. In one embodiment, the working fluid is delivered to a cylinder in which it expands, so as to move a piston. In one embodiment, the working fluid is fuel. In one embodiment, after the working fluid expands in the cylinder, it is recovered and burned in a combustion chamber, which is in fluid communication with the vortex tube. In one embodiment, the working fluid is water.

The disclosure relates to a method for operating an internal combustion engine in a six-stroke mode, wherein the engine comprises at least one cylinder with a reciprocating piston, each cylinder having at least one inlet and outlet valve. The method involves performing a first stroke where a gas comprising at least air is induced into a combustion chamber from an intake conduit; a second stroke where the gas and injected fuel is compressed; a third stroke where the compressed fuel/gas mixture is expanded following an ignition; a fourth stroke where combusted exhaust gas is expelled through a catalyst body into a first exhaust conduit; a fifth stroke where pressurized fuel and pressurized heated water is injected into the combustion chamber to be expanded; and a sixth stroke where steam and gaseous fuel mixture is expelled through the catalyst body into a second exhaust conduit.

An ECU controls a passage switch valve according to the operation state of an engine, to control the temperature of intake air introduced into the engine, by selectively causing outside air from an outside air inlet, high-temperature air from a high-temperature passage, or mixed air comprising the outside air and the high-temperature air to flow towards the downstream side of an intake passage. The ECU calculates the MBT ignition timing and the knock limit ignition timing based on detection results of sensors, and controls the passage switch valve such that, when the knock limit ignition timing is at a more advanced angle than the MBT ignition timing, the high-temperature air or the mixed air is introduced into the engine, and when the knock limit ignition timing is the same as or at a more delayed angle than the MBT ignition timing, the outside air is introduced into the engine.

Engines, systems, devices, software, and methods of the present invention provide increased fuel efficiency and emission performance. The engine may include a magnesium alloy cast engine block cast as a mono-block with or without a ceramic inner core and including one or more cylinders designed to provide compression ratio of 10:1 to 14:1. Each cylinder may include one or more laser igniters, one or more supercritical fuel injectors configured to inject the fuel near or in a supercritical state, and carbon dioxide, which may be in the form of engine exhaust gas. The fuel may be diesel, gasoline, or other suitable hydrocarbons that may be cracked into smaller molecules prior to be injected into the cylinder.

An injector model for atomization of liquid fuel using a low pressure atomized gas. The model is focused to mix a volume of liquid fuel with a volume of corresponding atomizing gas to obtain a pressurized liquid fuel-gas mixture. This liquid-gas mixture is ejected through a discharge orifice into a lower combustion chamber pressure, as a result of which the liquid fuel breaks up into ligaments. The atomized gas emerges from the liquid fuel-gas mixture as a result of pressure jump and further enhances this break-up of liquid fuel into smaller droplets and promotes combustion of these droplets in the chamber.