Study on dual-spark ignition rapid combustion characteristic of opposed-piston two-stroke GDI engine

The mixture formation and combustion process of an opposed-piston two-stroke (OPTS) gasoline direct injection (GDI) engine was carried out by numerical simulation. The effects on in-cylinder combustion and engine performance in different ignition ways of dual-spark ignition have been compared and analyzed. The dual-spark ignition system were installed on cylinder liner could make the in-cylinder combustion more stable and faster. It was benefit for increasing the thermal efficiency and avoiding the knock. Compared with single-spark ignition, dual-spark ignition could shorten flame propagation distance and accelerate flame propagation. Compared with single-spark ignition and synchronous dual-spark ignition models, the rapid combustion period of asynchronous ignition model was shorter, which was helpful to fast burning. In 6000r/min and 15kW full load case, the best ignition angle step of asynchronous ignition was about 10° crank angle (CA). When the initial ignition angle was the same, the ignition angle step of asynchronous ignition was smaller and the antiknock was worse.