There's been a lot of development activity around flying vehicles recently, but the Air Force wants a shortcut to an unmanned electric vertical takeoff and landing (eVTOL) concept for urban transport.

Development of compact, efficient rotary internal-combustion engines able to run on jet fuel has been boosted by U.S. Army contracts to advance the technology for unmanned-aircraft propulsion and ...

Everyone generally knows about piston and rotary engines, with many a flamewar having been waged over the pros and cons of each design. The “correct” answer is thus to combine both into a single ...

Pop the hood on a classic Mazda RX-7 or RX-8 and the engine bay looks oddly empty. That is the charm of the rotary engine: a compact lump of metal that trades pistons and valves for a spinning ...

The supercharged 25-hp XTS-210 rotary engine is intended to fill a gap on the mobile power market. Credit: LiquidPiston LiquidPiston has launched a 25-hp heavy-fuel rotary engine that could power ...

A German engineer, Felix Wankel, is credited with developing the world's first rotary engine in the 1950s. Wankel rotary engines use a triangular rotor spinning in a semi-oval case on an eccentric ...