Which type of engine has been used to power airships and/or dirigibles?

Hindenburg’s Daimler-Benz engines were also rather advanced, based on the MB-502 engine designed for German E-boats (high-speed motor torpedo boats) as part of the Nazi’s rearmament program.

16-cylinder Daimler Airship Engine

Each of Hindenburg’s four LOF-6 (DB-602) 16-cylinder engines had an output of 1320 hp @ 1650 RPM (maximum power), and 900 hp @ 1480 RPM.

The normal cruise setting was 1350 RPM, generating approximately 850 hp, and this setting was usually not adjusted during an ocean crossing.  The engines were started with compressed air, and could be started, stopped, and reversed in flight.

Using 2:1 reduction gearing, each engine drove a 4-bladed, fixed-pitch, 19.7′ diameter metal-sheathed wooden propeller (created from two 2-bladed props fused together).

 ( http://www.airships.net/ )

in software engineering and computer science, abstraction is: the process of removing physical, the way that different data types interact, is the beginning of abstraction.