sisämoottorit

Sisämoottorit, commonly known as internal combustion engines, are heat engines where the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. The expansion of the hot combustion gases produces useful work for an external mechanism. This is different from external combustion engines, such as steam engines, where the heat is transferred to the working fluid by a separate heat source.

The most common types of internal combustion engines are the four-stroke and two-stroke engines. The four-stroke engine completes a power cycle with four distinct piston strokes: intake, compression, power, and exhaust. The two-stroke engine completes a power cycle in only two strokes, combining the intake and compression, and the power and exhaust strokes. Internal combustion engines are widely used in automobiles, motorcycles, aircraft, and many other applications due to their high power-to-weight ratio and efficiency.

The fuel used in internal combustion engines can vary, but common examples include gasoline, diesel fuel, and natural gas. The combustion process generates high temperatures and pressures, which are converted into mechanical energy. Emissions from internal combustion engines can include pollutants such as carbon monoxide, nitrogen oxides, and particulate matter, leading to ongoing research and development in emission control technologies and alternative engine designs.