Influence of Nozzle Geometry on Spray Characteristics in Non-evaporative and Evaporative Conditions

An experimental study of real multi-hole diesel nozzles with different geometry in terms of conicity factor has been performed under current DI Diesel engines operating conditions.

A complete characterization of the internal nozzle flow and the sprays injected under non-evaporative conditions has been performed. The results of that study are applied in order to assist the analysis of spray in evaporative conditions. In this case, results of liquid-phase fuel penetration were obtained from a wide optical access engine operating under non-reacting conditions.

From these measurements, a comparison of the results with a theoretical Diesel spray model in evaporative conditions has been carried out. This comparison has allowed the determination of the dependence of stabilized liquid length on injection pressure, ambient conditions and nozzle geometry.