空气辅助燃料直喷嘴瞬态燃料喷射行为研究
The transient behaviour of the fuel spray from an air-assisted fuelinjector in a constant volume chamber has been investigatedexperimentally. The relative Sauter mean diameter (SMD) of thespray droplets was determined using planar laser inducedfluorescence (PLIF) and planar Mie scattering. Planar images ofthe ensemble averaged relative SMD with various injectionconditions were obtained by calculating the ratio between the twolaser light intensities at a given point. The penetration length andthe spray shape factor were also obtained. The ensembleaveraged results suggest the existence of vortices that are shedfrom the injector tip, and which entrain the smaller droplets.Results also show that the characteristics of the injector varyweakly with several particular injection parameters, notably thefuel injection pressure and the delay between fuel and airinjection.