Effects of Injection Timing on Air-Fuel Mixing in a Direct-Injection Spark-Ignition Engine

970625

02/24/1997

Event
International Congress & Exposition
Authors Abstract
Content
Multidimensional modeling is used to study air-fuel mixing in a direct-injection spark-ignition engine. Emphasis is placed on the effects of the start of fuel injection on gas/spray interactions, wall wetting, fuel vaporization rate and air-fuel ratio distributions in this paper. It was found that the in-cylinder gas/spray interactions vary with fuel injection timing which directly impacts spray characteristics such as tip penetration and spray/wall impingement and air-fuel mixing. It was also found that, compared with a non-spray case, the mixture temperature at the end of the compression stroke decreases substantially in spray cases due to in-cylinder fuel vaporization. The computed trapped-mass and total heat-gain from the cylinder walls during the induction and compression processes were also shown to be increased in spray cases. These thermodynamic features are shown to change with injection timing and they indicate the potentials of increasing engine thermal efficiency and power density in a direct-injection spark-ignition gasoline engine.
Meta TagsDetails
DOI
https://doi.org/10.4271/970625
Pages
15
Citation
Han, Z., Reitz, R., Yang, J., and Anderson, R., "Effects of Injection Timing on Air-Fuel Mixing in a Direct-Injection Spark-Ignition Engine," SAE Technical Paper 970625, 1997, https://doi.org/10.4271/970625.
Additional Details
Publisher
Published
Feb 24, 1997
Product Code
970625
Content Type
Technical Paper
Language
English