Journal of ILASS-Korea (한국분무공학회지)
- Volume 10 Issue 4
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- Pages.47-53
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- 2005
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- 1226-2277(pISSN)
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- 2288-9051(eISSN)
Effect of ambient conditions on the spray development and atomization characteristics of a gasoline spray injected through a direct injection system
분위기 조건이 직접 분사식 가솔린 분무의 발달 과정 및 미립화 특성에 미치는 영향
Abstract
This paper presents the effects of ambient pressure on atomization characteristics of high-Pressure injector in a direct injection gasoline engine both experimentally and numerically. The atomization characteristics such as mean droplet size, mean velocity, and velocity distribution were measured by phase Doppler particle analyzer. The spray development, spray penetration, and global spray structure were visualized using a shadowgraph technique. In order to investigate the atomization process numerically, the LISA-DDB hybrid model was utilized. This breakup model assumes that the primary breakup occurs when the amplitude of the unstable waves is equal to the radius of the ligament of liquid sheet near the nozzle and the droplet deformation induces the secondary breakup. The results provide the effect of ambient pressure on the macroscopic and microscopic behaviors such as spray development, spray penetration, mean droplet size, and mean velocity distribution. It is also revealed that the accuracy of prediction of LISA-DDB hybrid model is pretty good in terms of spray developing process, spray tip penetration, and SMD distribution.
Keywords