Influence of Nozzle Sac Volume on Diesel Spray Droplet Sizes

Abstract

The influence of nozzle sac volume and associated changes in the fuel hole upstream flow on the spray atomization, velocity and penetration were studied. Four injectors, designed for applications in 1 litre per cylinder diesel engines, were investigated with the same 215 bar injector nozzle opening pressure and fuel flow quantity. A Malvern 2600c Series diesel spray laser diffraction spray analyser was used. Significant differences in the spray characteristics were found which helped to explain some of the emission differences between the four injectors.