heat engine

American  

noun

Thermodynamics.

1. a mechanical device designed to transform part of the heat entering it into work.

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heat engine British  

noun

1. an engine that converts heat energy into mechanical energy

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Etymology

Origin of heat engine

First recorded in 1890–95

Example Sentences

Depending on conditions, it can function as a refrigerator, act as a heat engine, or amplify thermal transport.

From Science Daily • Jan. 29, 2026

Nearly two centuries ago, French physicist Sadi Carnot established the theoretical maximum efficiency that any heat engine can achieve.

From Science Daily • Jan. 22, 2026

“You can think of a hurricane as a heat engine where the ocean is the fuel … so giving it warmer water is basically like higher-octane fuel,” Hazelton said.

From Seattle Times • Sep. 4, 2023

We know from the second law of thermodynamics that a heat engine cannot be 100% efficient, since there must always be some heat transfer Qc to the environment, which is often called waste heat.

From Textbooks • Aug. 12, 2015

A gas engine is a heat engine in which the working fluid is atmospheric air and the fuel an inflammable gas.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" by Various