external combustion?

Yes, for instance, the steam engine.

Yes. A steam engine, for example, heats a liquid which turns into a gas, and the gas pressure operates the engine. The combustion takes place external to the cylinder, therefore it is an external combustion engine.

I once had a Toyota where combustion took place externally as well, but not for very long.

--scott

A fire engine. This engine is used to visit external combustion.

Huw

Yes:

All sarcasm aside, an "internal combustion" engine is one in which the combustion by-product gasses are themselves the working fluid that drives the engine. Examples are the piston engine (obvious) and the gas turbine (less obvious because a turbine engine isn't actually sealed) and a rocket engine (also open on one end)

Examples of an "external combustion" engine are those in which a heat source acts through a heat exchanger on another fluid that is the working fluid of the engine. Examples would be a steam engine or a Stirling engine. If you allow the term "combustion" to apply to heat sources other than actual combustion (nuclear fission or fusion, for example) then a few other real-world engines fall in the "external combustion" catgory, such as nuclear generating stations, nuclear aircraft carrier turbines, and the experimental nuclear-powered turbojet engines from the 1950s. Plus a few hypothetical ones, such as plasma drives for space vehicles.

Not forgetting 'Warp Drive' which uses dilithium crystals IIRC. And the there is the Tardis, but only Time Lords know whether any combustion is involved in time travel. I'm betting not.

Huw

Apart from the steam engine, aready mentioned, you might also consider rocket engines, tho this might require definition of "external:.

Yes. Steam engines were the first example, then internal combustion engines were based on the same principle, piston, crank, wheel. Androcles

Stirling engine!

Sure, anything with a boiler qualifies.

Mati Meron | "When you argue with a fool, snipped-for-privacy@cars.uchicago.edu | chances are he is doing just the same"

In addition to those mentioned, there is also the Stirling engine.

Ooops, just noticed that BobG got there before me.

Can you say "steam engine"? Sure... I knew you could...

Nope. The combustion by-product gas is the working fluid of the engine, therefore its internal combustion.

Don't be silly. Warp drive is powered by a matter/antimatter reaction, the dilithium crystals just control it. :-p

People are gonna think we've been "combusting" some herbal material the way this thread is going...

Did you ever hold a lighted match under a horse's tail just as the horse was in the process of releasing a blast of flatus. That comes pretty close to describing external combustion, and the horse's reaction is a good example of the engine effect. ;-)