Gasoline and diesel versions of an internal-combustion engine that promises 60% fuel efficiency and an 80% reduction in emissions are being built in preparation for demonstration next year.

The split-cycle Scuderi Air-Hybrid Engine is being developed with $8 million of private investment and could be used in general aviation aircraft.

In a split-cycle engine, the conventional four-stroke cycle – induction, compression, power and exhaust in a single cylinder – is divided between separate compression and power cylinders, which can be optimised independently. Gas is compressed in one cylinder, then transferred to the other for combustion.

The engine’s inventors claim to have solved a number of design problems encountered by split-cycle developers, such as accurately igniting combustion, which is necessary to achieve the claimed efficiency – 60% compared with 33% for conventional engines.

Prototype engines are being constructed at the Texas-based Southwest Research Institute.


Source: Flight International