Diesel nozzle geometry influence on spray liquid-phase fuel penetration in evaporative conditions

An experimental study of real multi-hole Diesel nozzles is performed under current DI Diesel engines operating conditions. The aim of the investigation is to study the influence of orifice geometry on the flow at the nozzle exit and to analyse its effect on the spray in evaporative conditions. Special attention is taken in the study of the influence of cavitation on the orifice internal flow and spray development. The spray liquid-phase fuel penetration has been characterized. The visualization was made in a wide optical access engine for different operating conditions. From the measurements, the dependencies of nozzle geometry, injection conditions and ambient conditions on liquid-phase length were studied and analyzed. A model for liquid-phase fuel penetration in diesel sprays based on nozzle flow parameters has been proposed and validated.