커먼레일 시스템의 분사율과 초기분무 거동

Abstract

Transient nature of common-rail diesel sprays was characterized at the initial stage of fuel injection, the effects of injection rate being taken into account. Direct photography and shadowgraph technique were used to obtain macroscopic spray images at several different experimental conditions. Discussed in detail were the effects of rail pressure, ambient gas density and presence of nozzle sac volume on spray behaviors. Based on the measurement data far injection rates, the asymptotic profiles of spray penetrations were found at early and late stage of injection. The changes of spray volume were correlated with the measured injection rates. It was found that the initial spray penetration is well correlated with the amount of fuel injected. The increase of injection rate during the injection period was observed to produce smaller spray cone angle.