研究目的

The experimental research of LASER ignition use in the spark ignition engine.

研究成果

The experimental results obtained from the LASER ignition used in the spark ignition engine compared to the classic ignition system have led to several important conclusions. The in-cylinder maximum pressure increases with almost 2 bar on LASER use. Also the maximum pressure rise rate registered for classic ignition increases from 1.6 bar/CAD up to 1.8 bar/CAD for LASER ignition. The maximum pressure appears earlier per cycle on LASER use, the angle of maximum pressure being reached 2 % closer to TDC. When the LASER ignition system is used, the initial phase ends around 4 CAD earlier per cycle comparative to spark ignition system. The maximum values of heat release rate and heat release law for SPI are comparable to the values registered for LPI, but the heat release rate and the heat release law are reached almost 5 CAD earlier per cycle for LASER ignition. The initial phase of the combustion decreases by 25% at LASER ignition use versus the classic ignition system. The stage of 10% heat release per cycle is reached 4 CAD sooner per cycle in the case of the LASER ignition system. The reduction of the duration of the initial phase of combustion is due to a much higher energy developed by LASER ignition system versus the spark ignition system. 50% of mass fraction burned per cycle is achieved before TDC, 3 CAD earlier for LASER ignition.

研究不足

The most critical problem of LASER ignition use during the experimental investigation was the possibility of destroying the optical element coatings. The optical element is designed to construct the focusing line and during engine operation damage of the lenses from the pump line can sometimes appear.