cetane number

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cetane number

a measure of the quality of a diesel fuel expressed as the percentage of cetane in a mixture of cetane and 1-methylnapthalene of the same quality as the given fuel
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Cetane Number

 

an arbitrary quantitative characteristic of the spontaneous combustion of diesel fuels in the cylinder of an engine. As is the case with the octane number of a gasoline, the cetane number of a diesel fuel is determined under strictly controlled conditions; cetane and α-methylnaphthalene, the cetane numbers of which are assumed to be 100 and 0, respectively, are used as the standard references. The ignition quality of a fuel being tested is characterized by determining the composition of a blend of cetane and α-methylnaphthalene that has an equivalent ignition quality. Quantitatively, the cetane number indicates the percentage by volume of cetane in the reference blend. The higher the cetane number of a diesel fuel, the quicker the ignition of the fuel in the engine, the smoother the pressure increase, and the quieter the operation of the engine. The cetane numbers of present-day diesel fuels range from 40 to 55. Additives, such as organic peroxides and nitroalkanes, are used to improve the cetane number.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

cetane number

[′sē‚tān ‚nəm·bər]
(chemical engineering)
The percentage by volume of cetane (cetane number 100) in a blend with α-methylnaphthalene (cetane number 0); indicates the ability of a fuel to ignite quickly after being injected into the cylinder of an engine.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
A low cetane fuel (below 40) will cause visible white smoke, poor fuel economy, and lack of power in cold ambients--whereas a higher cetane rating will result in better engine performance, better fuel economy and better exhaust emissions.
Isocetane (2,2,4,4,6,8,8-heptamethylnonane) with a cetane rating of 15 because it ignites poorly in a diesel engine and cetane (n-hexadecane), with a cetane rating of 100 because it ignites easily, have been used as the reference fuels since 1962.
EC Diesel fuel has a higher cetane rating with a lower sulfur and aromatics content than current diesel formulations, the company said.
"In addition," says Freese, "it can help compensate for differences in fuel quality arising from variances in the fuel's cetane rating." It will be adapted to other GM diesels in the future.
That's why the Le Mans-winning Audi R10 race car runs on a variant of Shell's commercial "V-Power" diesel, which blends a natural gas-derived GTL component (it has a high cetane rating and minimal sulfur or aromatics) with conventional diesel fuel.
In addition, the engine is fitted with pressure sensors that help the engine compensate for the regional difference in cetane ratings found in U.S.