TITLE:
Numerical Accuracy of the Kiva4 Code under Different Ignition Timing on the Combustion Characteristics of Gasoline in a Spark Ignition Engine
AUTHORS:
Joseph Lungu, Lennox Siwale, Edwin Luwaya
KEYWORDS:
Combustion, Kiva4, Accuracy, Ignition Timing, Gasoline
JOURNAL NAME:
Journal of Power and Energy Engineering,
Vol.6 No.11,
November
28,
2018
ABSTRACT: The purpose of this work was to show that kiva4 is more accurate than kiva3vr2 under different ignition timings. The numerical accuracy of kiva4 was compared with the numerical results obtained by other researchers who used kiva3vr2 as the simulation code. The combustion characteristics of gasoline under different ignition timings are obtained using the kiva4 code. For achieving this, two cases were investigated; a complete engine cycle was successfully simulated using a four-valve pent-roof engine and a comparison was made with experimental results by other researchers. At a constant speed of 600 rpm, a BASF (Badische Anilin-und Soda Fabrik) octane rating engine-single cylinder was used where ignition timing was changed in the range of 4° BTDC to 18° BTDC. Kiva4 generates more accurate results than kiva3vr2. The experimental results were more in agreement with kiva4 than kiva3vr2 results. The average temperature and pressure in kiva4 were 640 K and 16.48 bars while in kiva3vr2 were 600 K and 14.83 bars, the peak temperature and pressure in kiva4 were 2316.3 K and 21.5 bars while in kiva3vr2 were 2171.5 K and 19.4 bars. The peak temperature and pressure increase with increasing spark advance until the most favorable instant time is determined. Best performance was achieved when the ignition time was set to 10 degrees before top dead center.