Internal combustion models of engine:

The engines which develop power by combustion of fuel within the engine are called internal combustion engines. The examples of internal combustion engines are diesel and petrol engines used in cars, trucks etc.  The engines in which power is developed by combustion of fuel outside the engine are called external combustion engines such as steam engine. In the internal combustion engine power is developed from combustion of fuel which is chemical reaction. Because of combustion of fuel hot gases are produced at adequately high pressure. This pressure is taken in use to move the piston linearly. This linear motion of piston is converted into rotary motion afterwards.