The internal combustion engine is a heat engine in which the burning of a fuel occurs in a confined space called a combustion chamber.

内燃机是一种热机，燃料在其被称为燃烧室的密封空间内燃烧。

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It verified that there is a free space limit in motor combustion chamber. This limit is a value that affects the stable and unstable combustion.

结果发现，发动机燃烧室存在一个自由容积的阈值，这个值是影响发动机稳态燃烧和非稳态燃烧的界限值。

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Instead, two pistons face each other and the space between them serves as the combustion chamber.

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