Definitions for compression ratio
com·pres·sion ra·tio

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1. compression rationoun

   The ratio of the volume between the cylinder head of an internal combustion engine and the piston before and after the compression stroke

2. compression rationoun

   The ratio of the size of compressed data after the execution of some compression algorithm to the size of the original data.

WikipediaRate this definition:0.0 / 0 votes

1. Compression ratio

   The compression ratio is the ratio between the volume of the cylinder and combustion chamber in an internal combustion engine at their maximum and minimum values. A fundamental specification for such engines, it is measured two ways: the static compression ratio, calculated based on the relative volumes of the combustion chamber and the cylinder when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke.The dynamic compression ratio is a more advanced calculation which also takes into account gasses entering and exiting the cylinder during the compression phase.

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1. Compression ratio

   The compression ratio of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity. It is a fundamental specification for many common combustion engines. In a piston engine, it is the ratio between the volume of the cylinder and combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke. Picture a cylinder and its combustion chamber with the piston at the bottom of its stroke containing 1000 cc of air. When the piston has moved up to the top of its stroke inside the cylinder, and the remaining volume inside the head or combustion chamber has been reduced to 100 cc, then the compression ratio would be proportionally described as 1000:100, or with fractional reduction, a 10:1 compression ratio. A high compression ratio is desirable because it allows an engine to extract more mechanical energy from a given mass of air-fuel mixture due to its higher thermal efficiency. This occurs because internal combustion engines are heat engines, and higher efficiency is created because higher compression ratios permit the same combustion temperature to be reached with less fuel, while giving a longer expansion cycle, creating more mechanical power output and lowering the exhaust temperature. It may be more helpful to think of it as an "expansion ratio", since more expansion reduces the temperature of the exhaust gases, and therefore the energy wasted to the atmosphere. Diesel engines actually have a higher peak combustion temperature than petrol engines, but the greater expansion means they reject less heat in their cooler exhaust.

How to pronounce compression ratio?

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How to say compression ratio in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of compression ratio in Chaldean Numerology is: 9

2. Pythagorean Numerology

   The numerical value of compression ratio in Pythagorean Numerology is: 2

References

1. ^ Wiktionary
   https://en.wiktionary.org/wiki/Compression_Ratio
2. ^ Wikipedia
   https://en.wikipedia.org/wiki/Compression_Ratio
3. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=compression ratio