Correlation Between the Liquid Fuel Properties Density, Viscosity and Surface Tension and the Drop Sizes Produced by an SI Engine Pintle-Type Port Fuel Injector

Droplet size measurements were performed on the spray from a pintle-type gasoline injector. These quantified the influence of the fuel properties, relative fuel/air velocity and manifold air density upon the droplet sizes.

Dimensional analysis and knowledge of the atomization process was used to derive equations predicting mean droplet diameters. Constants and exponents used in these equations were evaluated by correlation with the measured data.

The equations were used to predict the individual or combined influence of the above variables.

It is concluded that the influence of variations in properties between production gasolines on atomization is likely to be small.