Computations and Experiments of Single-Point Autoignition Gasoline Engine with Colliding Pulsed Supermulti-Jets, Single Piston and Rotary Valve

A new engine concept (Fugine) based on colliding pulsed supermulti-jets was proposed in recent years, which is expected to provide high thermal efficiencies over 50% and less combustion noise. Theoretical analyses indicate a high potential for thermal efficiency over 60%. Three types of prototype engines have been developed. The first prototype engine based only on the colliding of pulsed supermulti-jets with fourteen nozzles has no piston compression, while the second type equipped with a low-cost gasoline injector in the suction port has a double piston system and eight jet nozzles. Combustion experiments conducted on the second prototype gasoline engine show high thermal efficiency similar to that of traditional diesel engines and lower combustion noise comparable to that of traditional spark-ignition gasoline engines. This paper presents the third prototype engine: a single-piston engine having a rotary valve, which induces strong point compression produced by twenty-four pulsed multi-jets injected from suction nozzles. Negative pressure generated by expansion due to piston motion under a closed rotary valve condition results in strong jets going to the cylinder center. This third engine has no compression due to piston motion. Unsteady three-dimensional computations for this engine including spray calculations of liquid gasoline, subsonic and supersonic turbulent flows, and combustion phenomena show the potential for very high combustion efficiency over 95%. Based on the result, combustion experiments of the engine were started. The colliding of the pulsed supermulti-jets causes combustion to occur.