What is Engine? What Are The Types of Heat Engine?

Definition of Engine:

Any device which converts energy from one form to another is known as an engine. Energy is in various forms like mechanical energy, chemical energy, wind energy, flow energy, electric energy, magnetic energy, sound energy, light energy, etc.

Energy can be converted from one form to another (First law of Thermodynamic).

Any device which converts the chemical energy of fuel into thermal energy and converts this thermal energy into mechanical energy, known as a heat engine. All automobiles engines, gas turbine engines, steam turbine engines, etc. are heat engines. We will focus only on heat engines on this website.

Basic Types of heat Engines:

Mainly there are two types of heat engines. The first one is known as the Internal Combustion Engine (IC Engine) and the other one is known as the External Combustion Engine (EC Engine). Their engines are further classified into the reciprocating engines and rotary engines.

Internal Combustion Engine:

An engine in which combustion of fuel (Burning of Fuel or converting of chemical energy of fuel into thermal energy) takes place into a closed cylinder is known as an internal combustion engine. All automobile engines are internal combustion engines. These engines have higher thermal efficiency low weight to power ratio.

These engines are further classified into Rotary Engine (Wankel engine) and Reciprocating Engine (Diesel and Petrol Engine).

Reciprocating internal combustion engines are used in automobiles, motorcycles, boats, slow speed aircraft, etc.

The rotary internal combustion engine is used in aircraft (open cycle gas turbine)

External Combustion Engine:

An engine in which combustion of fuel takes place outside of the cylinder or engine is known as an external combustion engine. For example for in steam engine, the combustion of fuel takes place outside which converts water into steam and this high-pressure steam used to do mechanical work.

These engines are further classified into rotary (Steam Turbine) and reciprocating Engines (Steam Engine).

External combustion engines have wide applications in power plant engineering.