Diesel engine

From Wikipedia, a free encyclopedia written in simple English for easy reading.

The name diesel refers to an engine invented by a German named Rudolf Diesel in the late 19th century.

Most engines need a system called an ignition system - one which uses an electric spark - in order to burn the mix of fuel and air which makes power. Other types of ignition sytems used air a type called compressed air starting which is basically forcing compressed air into the cylinders from an external source such as an air compressor. A diesel does not. It burns a fuel similar to heating oil through very high compression or pressing together of the mix. A tiny bit of fuel is injected, or forced, into the engine's cylinders at just the right moment. Since gases heat when they are pressed together, the compression of the air and fuel mix cause the mix to explode within the cylinder.

Diesel engines make very good use of the fuel they burn. They also make lots of torque (pronounced "tork"), or twisting power. This makes a diesel engine a good choice in heavy equipment like trucks, trains and construction machines. The very big trucks you see on the road have diesels in them. So do trains, unless they are steam-powered. Sometimes, even the torque of a diesel engine is not enough to run such big machines. To boost power, large diesels often have a device called a turbocharger attached. A turbocharger is a type of turbine, which is a thing used to move air at very high speed. Jet engines often work with a turbine. In the diesel, pressure from the exhaust spins the turbocharger at very high speed. Air is then forced back into the engine. Since any engine is a sort of air pump, the more air you can put through it, the more power it makes. That's where the turbocharger helps. A diesel fitted with a turbocharger is called a turbodiesel. The whistling sound you sometimes hear when you are near one of these engines is caused by the turbocharger, or "turbo" for short.

A diesel engine can also be made to run on vegetable oil made from old cooking oil. This type of fuel is called biodiesel. Running a diesel engine on biodiesel fuel has a funny effect. The exhaust smells like French fries!

Running a diesel engine on vegetable oil is not a new idea. The engine that Rudolf Diesel used to demonstrate his new idea ran on peanut oil.