ENGINES
Engine is a machine for converting energy into motion or
mechanical work. The energy is usually supplied in
the form of a chemical fuel, such as oil or gasoline, steam, or electricity, and the
mechanical work is most commonly delivered in the form of rotatory motion of a shaft.Though the term motor is sometimes restricted to engines that transform electrical energy into mechanical energy ,engines are often called motors
Engines are usually classified according to the form of energy they utilize, as steam, compressed air, and gasoline; the type of motion of their principal parts, as reciprocating and rotary; the place where the exchange from chemical to heat energy takes place, as internal
combustion and external combustion; the method by which the engine is cooled, as air-cooled or water-cooled; the position of the cylinders of the engine, as V, in-line, and radial; the number of strokes of the piston for a complete cycle, as two-stroke and four-stroke; the type of cycle, as Otto (in ordinary gasoline engines) and diesel; and the use for which the engine is intended, as automobile and airplane engines. ,Other specialized engines are the windmill, gas turbine, steam turbine, and rocket and jet engines.