External combustion engine
The external combustion engine means that its fuel is burned outside the engine. It was invented by R. Stirling of Scotland in 1816, so it is also called the Stirling engine. The engine converts the heat generated by this combustion into kinetic energy. Watt’s modified steam engine is a typical external combustion engine. When a large amount of coal is burned to produce heat and heat water into a large amount of water vapor, high pressure is generated. The high pressure pushes the machine to do work, thus completing the transformation from thermal energy to kinetic energy.
internal combustion engine
If you understand what an external combustion engine is, you also know what an internal combustion engine is. The internal combustion engine is a reciprocating piston engine. The biggest difference between this type of engine and an external combustion engine is that its fuel is burned inside. There are many types of internal combustion engines. Common gasoline engines and diesel engines are typical internal combustion engines.
In addition, there are gas turbines, which are characterized by combustion to produce high-pressure gas, and the high pressure of the gas is used to drive the blades of the gas turbine to rotate, thereby outputting power. Gas turbines are used in a wide range, but because it is difficult to finely adjust the output power, gas turbines are rarely used in cars and motorcycles, and only some racing cars have used gas turbines.
Jet engine refers to an engine that directly generates reaction thrust by the high-speed airflow from the nozzle. Widely used as a power plant for aircraft. The fuel and oxidant react chemically in the combustion chamber to release heat energy. Then the heat energy is converted into the function of adjusting the air flow in the nozzle. In addition to fuel, oxidants carried by aircraft are called rocket engines, including solid fuel rocket engines and liquid fuel rocket engines.