Computations of Air/Fuel Preparation Process in a Port-Injected Spark-Ignition Engine During Cold-Starting Phase

Abstract

A numerical study has been performed of the air/fuel preparation process in a cold-starting port-injected spark-ignition engine. The latest models were implemented for spray impingement and multicomponent vaporization of the droplet and wall film accounting for finite diffusion in the liquid. The infinite diffusion model was found insufficient for predicting vaporization in this engine, and the single-component fuel representation yields results significantly different from those from the multicomponent one. The operating parameters studied included injection timing, swirl, speed, target path, enrichment, and fuel accumulation. In-cylinder measurements were compared and good agreement was achieved. Detailed quantitative analysis of the air/fuel preparation of the engine was reported.