A new design developed by U.S. Department of Energy Princeton Plasma Physics Laboratory (PPPL) researchers to improve thermal cycle efficiency and reduce pollutant emissions from gasoline-powered internal combustion engines (ICEs) has been patented.

After realizing that a spinning gas could allow engines to operate at lower temperature more efficiently than conventional internal combustion engines, the team translated findings from their plasma spinning and compression research to the performance improvement of these engines.

The eight-cycle engine is designed with a main cylinder and main piston that are relatively axially displaceable along a main axis to define a variable volume main working chamber. One valve is configured to admit air and fuel into the working chamber to form an air/fuel mixture. The main cylinder is structured to cause this mixture to spin rapidly enough to affect its heat capacity and lead to compression and ignition. Mechanical energy is extracted from the ignited spinning air/fuel mixture.

While the patented findings remain theoretical, the maximum temperature during combustion may be much lower than conventional engines temperatures, even as low as approximately 652° C to reduce nitrogen oxides emissions. In this case, the ignited spinning air/fuel mixture may produce an efficiency gain much greater than engines that do not use a spinning air/fuel mixture.