external-combustion engine

noun

1. a heat engine in which the working fluid is heated in an external boiler or heat exchanger and is thus isolated from the process of fuel combustion

Example Sentences

One is that because, like a steam engine, a Stirling is an external-combustion engine, it can run on a variety of fuels.

From Economist

The Prius has been the world's best-selling hybrid vehicle, helping Toyota grab 70 percent of the U.S. market for vehicles powered by a combination of an external-combustion engine and electric motor.

From Reuters