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 ...

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.

LiquidPiston is to study the application of its rotary diesel engine technology to hybrid-electric propulsion systems for unmanned aircraft and advanced air mobility vehicles under a contract from the ...

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 ...