Engine
A machine which drives heat energy from combustion of fuel and converts it into mechanical work is termed as engine. As it converts heat energy into mechanical work it is called as ''heat engine''.
Heat engines can be mainly classified into two types
- EXTERNAL COMBUSTION ENGINES:- In this case combustion of fuel takes place outside of the cylinder. Steam engines are the examples of this engine where the heat of combustion is employed to generate steam which is used to move a piston in a cylinder. These engines are generally used for driving locomotives, ships and for generation of electric power etc.
- INTERNAL COMBUSTION ENGINES:- In this case combustion of fuel with oxygen of the air occurs within the cylinder of the engine. The IC Engine group includes engines employing mixtures of combustible gases and air, known as gas engines, those using petrol,known as petrol engines and those using heavier liquid fuels, known as diesel engines.
Internal combustion engines are further classified into two types based on ignition of fuel:
- SPARK IGNITION ENGINE (SI ENGINE):- A spark ignition engine is an internal combustion engine, generally a petrol engine, where the combustion process of air fuel mixture is ignited by a spark from spark plug.
- COMPRESSION IGNITION ENGINE (CI ENGINE):- A compression ignition engine is an internal combustion engine, generally a diesel engine, where the combustion of fuel which is injected into the combustion chamber is ignited by heat of combustion.
IC Engines are also classified on the basis of working cycles
- TWO STROKE CYCLE ENGINE:- When the cycle is completed in one revolutions of crankshaft it is called as two stroke engine.
- FOUR STROKE CYCLE ENGINE:- When the cycle is completed in two revolutions of crank- shaft it is called as four stroke cycle engine.
- SUCTION
- COMPRESSION
- POWER
- EXHAUST
