Discharge coefficients for a diesel injector during cold starting conditions
Résumé
Most studies of sprays produced from diesel injectors are performed at "usual" ambient temperature. These studies focus on spray development and the impact of flow inside the injector nozzles. Various mechanisms can produce initial perturbations of the jet and depend on nozzle geometry--the cavitation phenomenon through the nozzle hole is one of these. Until recently, only a few studies have examined spray development for cold temperature conditions (i.e., below 273 K). The objective of this study is to provide data regarding the phenomena occurring in a diesel fuel jet above temperature conditions, representative of a cold start for a direct-injection compression ignition engine. In this study, the discharge coefficient has been estimated by performing experiments inside a climatic chamber, from 253 to 293 K, for three different fuels, namely, n-heptane, decane, and arctic diesel fuel.