Convegni ATI - Accesso riservato soci CTI

Autore: A. de Risi, T. Donateo, E. Montefrancesco, D. Laforgia

Collana: CA - 59 - Genova 2004

Note:
Improvements to the injection model of a modified version of the KIVA-3V code are presented. The enhancements consist of a hybrid breakup model implementation to better predict spray penetration under severe evaporating conditions. Computational results were verified against experimental data, acquired via a back-light photographic technique, for full-cone diesel sprays injectes into a constant-volume vessel in order to avoid uncontrolled influences due to in-cylinder engine air motion. The experimetnal investigation was carried out for 12 operating conditions, characterized by in-cell air temperatures ranging from 300K to 1085K. The injection pressure and duration was varied from 40 to 60 Mpa and from 400 to 600μs, respectively. A comparison between computational and experimental data was performed on macroscopic parameters such ad aspay penetration. The effect of different breakup models was investigated. The breakup was firstly calculated using the Kelvin-Helmholtz instability. In further investigations it was modelled accounting for both K-H and Rayleigh-Taylor instabilities and finally introducing a standard and enhanced TAB model. A new breakup model which includes a competition of all the above mentioned medels is presented.