Entire-spray mixing characteristics over time after the start of the injection using an image-processing technique for high-speed captured images Of Cr-Di fuel sprays

Diesel fuel sprays from a common rail injector were injected into a pressurized constant-volume chamber. The environmental gas density in the constant-volume chamber was 18 kg/m ³ , which is representative of the density in a typical diesel engine when the fuel injection process starts. Consecutive images of the diesel fuel sprays were captured with a high-speed camera at a constant time interval. The spray dispersion area with time after the start of the fuel injection was obtained. The spray dispersion area increased linearly with time after the start of the injection. The slope of the linear correlation line between the spray dispersion area and time after the start of the injection was steeper when the fuel injection pressure was higher. There was little effect on the slope of the linear correlation line with a change of the duration of the fuel injection time. The mixing characteristics of the entire spray injected from the common rail diesel injector were studied by analyzing the capture images. The mixing characteristics of all sprays over time after the start of the injection process were quantified by determining the pure-light-extinction intensity (PLEI) at each pixel for all of the sprays.