Definition
An internal combustion engine in which a triangular rotor turns inside an oval-shaped (epitrochoidal) housing, producing the four cycles of intake, compression, combustion, and exhaust through the rotor's motion rather than through reciprocating pistons. Also commonly known as a Wankel engine.
Plain English
An engine that uses a spinning rotor inside a curved housing instead of pistons that move up and down. As the rotor turns, the spaces between it and the housing change size, which draws in fuel and air, squeezes it, burns it, and pushes the exhaust out.
Context Anchor
Seen in aircraft powerplant study when comparing different engine designs and how they turn fuel into shaft power.
Derivation
Rotating combustion describes how the engine works: combustion happens around a rotating part rather than against a piston that moves back and forth. It is named after Felix Wankel, the German engineer who developed the design in the 1950s.
Why Pilots Care
Provides a high power-to-weight ratio and smooth operation, used in some light sport and experimental aircraft.
Analogy
Think of the difference between pedaling a bicycle in circles and pushing a pump handle up and down. Both can make motion, but the rotating combustion engine is built around circular motion rather than back-and-forth motion.
Intuition Check
Do not read “rotating combustion” as if the fire itself is spinning around. The key idea is that the engine’s internal rotor turns while combustion pushes it.
Example Sentence 1
The light sport aircraft was powered by a rotating combustion engine, giving it a smoother feel than the piston-engine trainers on the ramp.
Example Sentence 2
Some pilots prefer the RC engine for its compact size and reduced vibration in flight.