The Collaborative International Dictionary
Diesel \Diesel\, Diesel engine \Die"sel en`gine\ or Diesel motor \Die"sel mo`tor\ (d[=e]"zel). [After Dr. Rudolf Diesel, of Munich, the inventor.] A type of internal-combustion engine in which the air drawn in by the suction stroke is so highly compressed that the heat generated ignites the fuel (usually a heavy oil), the fuel being automatically sprayed into the cylinder under pressure. The Diesel engine has a very high thermal efficiency.
n. 1 an internal combustion engine which operates using diesel fuel 2 (context rail English) a diesel locomotive
The diesel engine (also known as a compression-ignition or CI engine) is an internal combustion engine in which ignition of the fuel that has been injected into the combustion chamber is caused by the high temperature which a gas achieves when greatly compressed ( adiabatic compression). This contrasts with spark-ignition engines such as a petrol engine ( gasoline engine) or gas engine (using a gaseous fuel as opposed to petrol), which use a spark plug to ignite an air-fuel mixture. In diesel engines, glow plugs (combustion chamber pre-warmers) may be used to aid starting in cold weather, or when the engine uses a lower compression-ratio, or both.
The diesel engine has the highest thermal efficiency ( engine efficiency) of any practical internal or external combustion engine due to its very high expansion ratio and inherent lean burn which enables heat dissipation by the excess air. A small efficiency loss is also avoided compared to two-stroke non-direct-injection gasoline engines since unburnt fuel is not present at valve overlap and therefore no fuel goes directly from the intake/injection to the exhaust. Low-speed diesel engines (as used in ships and other applications where overall engine weight is relatively unimportant) can have a thermal efficiency that exceeds 50%.
Diesel engines are manufactured in two-stroke and four-stroke versions. They were originally used as a more efficient replacement for stationary steam engines. Since the 1910s they have been used in submarines and ships. Use in locomotives, trucks, heavy equipment and electricity generation plants followed later. In the 1930s, they slowly began to be used in a few automobiles. Since the 1970s, the use of diesel engines in larger on-road and off-road vehicles in the US increased. According to the British Society of Motor Manufacturing and Traders, the EU average for diesel cars accounts for 50% of the total sold, including 70% in France and 38% in the UK.
The world's largest diesel engine is currently a Wärtsilä-Sulzer RTA96-C Common Rail marine diesel, which produces a peak power output of at 102 rpm.
Usage examples of "diesel engine".
To make bio-diesel the triglyceride molecules have to be broken down to separate out the glycerol, which is a useful byproduct of the whole process but not a good thing to burn in a modern computer-controlled diesel engine.
The shell hit the Russian between the last pair of road wheels and wrecked the tank's diesel engine.
Finished, they moved back to the truck, which started up and proceeded west on the fork to the main road, motoring off with the sound on a poorly muffled diesel engine.
The center hold held a Caterpillar diesel engine and its fuel tanks, one on each side.
The throaty rumble of his own diesel engine was answered by the THUNDER of two hundred others, and BOYAR started moving northeast through the hills.
The smell of the exhaust from the diesel engine came as a relief after the aroma of the town.
A minute later everyone aboard felt the vibration as the October's massive diesel engine cranked on battery power.
The throaty rumble of his own diesel engine was answered by the thunder of two hundred others, and BOYAR started moving northeast through the hills.
As I struggled to rise, my foot remained hooked in the line, briefly but enough to delay me, and already the massive roar of the big diesel engine seemed to be on top of me.
Powered by turbocharged diesel engine, it is capable of two hundred twenty kilometers an hour.
The four-cylinder diesel engine is tossed through a broken window and ends up in the stairwell.