Spark ignition combustion of direct injected flash boiling hollow cone spray

This paper demonstrates spark-ignition combustion of direct injected flash boiling spray using a hollow cone fuel injector in a constant volume combustion chamber. Different from previous studies on the combustion of flash boiling sprays, in this work the spark is fired during the fuel injection process with significant air–fuel mixture stratification. Effects of the ambient temperature and pressure are investigated to determine the effectiveness of flash boiling on the combustion process. Results show that under strong flash boiling conditions low luminosity bulky flame is obtained with little soot generation. Under non-flash boiling low ambient pressure conditions, fuel spray can impinge on the wall and forms liquid film deposition, which can cause pool fires on the walls. Generally speaking, the luminous zone expansion speed increases with increasing ambient pressure and the peak luminosity increases with increasing temperature. The peak combustion pressure increases with increasing initial ambient pressure. The peak pressure ratio can reach 10 under 0.2 bar and it decreases with increasing ambient pressure. The observed phenomenon is different from the previous studies and may have potential for the development of novel technology for combustion devices.