Injection Parameter Effects on Diesel Spray Characteristics

This paper reports efforts to study the effect of various injection parameters on macro characteristics of diesel sprays generated by a state-of-the-art common-rail injection system. The main purpose is to validate and extend various correlations available in the literature to the case of sprays generated by common-rail injection systems which are characterized by high injection pressures and small orifice diameters. Experiments were conducted by spraying into a quiescent atmosphere at room temperature. Densities close to in-cylinder conditions at the start of injection were established using pressurized nitrogen. While the measured macro characteristics - spray penetration length and spray cone angle - agreed well with established correlations, distinct deviations could be observed. Possible explanations for such deviations are discussed.