A Research on Fuel Spray and Air Flow Fields for Spark-Ignited Direct Injection using Laser Measurement Technology

The change of spray shape under different ambient pressure and the size distribution of fuel droplets from swirl injector were investigated. And, for the stratified-mixture operation in the vicinity of spark plug, fuel distribution after impingement on piston in motoring engine was examined in the cases of two different injector positions. Also, the influence of intake port geometry and piston top shape on in-cylinder air flow during intake to compression stroke was investigated. This paper concludes that, in tumble-based combustion strategy, locating swirl injector at intake side of cylinder head and making counter-rotating tumble increased in intake port geometry and conserved on bowl piston surface would be very effective for stratified combustion of spark-ignited direct injection engine.