An empirical correlation between spray dispersion and spray tip penetration from an edge detection of visualized images under the flow condition of a solid body rotating swirl

In this study, spray tip penetration and dispersion in high-pressure environment were simulated experimentally with an emphasis on the swirl effect. A rotating constant volume chamber was designed in order to generate a swirl that could be varied continuously with a flow field that closely resembled the solid-body rotation. An emulsified fuel was injected into the chamber and the developing process of fuel spray was observed. The effect of swirl on the spray dispersion was analyzed by measuring the dispersion area as a function of the spray tip penetration and the time after the start of the injection. The effect of swirl on the spray dispersion was quantified through getting a relationship between the swirl and the dispersion. The experimental results of the spray dispersion with time after the fuel injection process began showed similar characteristics to those of the spray tip penetration with time after the start of the fuel injection. The spray dispersion characteristics while varying the spray tip penetration were also investigated. The results showed that the spray dispersion depends linearly on the spray tip penetration, when it is small. As the spray tip penetrates into longer distance, the dispersion depends on the spray tip penetration to the power of 1.6.