RADIAL-DISTRIBUTION OF DROP SIZE IN STEADY FULL-CONE SPRAYS

Some measurements of drop size in full-cone sprays that are typical of automotive fuel injectors indicate a mean drop size that increases with distance from the axis, whereas other measurements indicate the opposite trend. Available models of full-cone sprays, on the other hand, always tend to produce a peak in mean drop size on the axis, with decreasing mean drop size in the radial direction. The location of large drops is important because they contain a significant fraction of the liquid mass. Through computations and comparisons with measurements it is argued that large drops can be at the periphery of full-cone sprays only if their initial angle is larger than that assumed in current drop formation models. The fact that the trajectory angles of such outer large drops are direct remnants of the drop formation process may be useful in the investigation of the drop formation process itself.