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
Affiliations: Department of Automotive Engineering, Seoul National
University of Technology, Seoul 139-743, Korea. E-mail: chlee5@snut.ac.kr
Abstract: 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.
Keywords: Emulsion Injection Visualization, Spray Dispersion, Solid Body Rotating Swirl, Spray Tip Penetration, Diesel Engine, Fuel Injection