Numerical investigation on effect of spark plug configuration on performance in an engine cylinder

Abstract

A numerical investigation of combustion inside single and twin-spark engines was performed to study the effect of a spark plug, positions and spark timings on engine performance. Improvement in engine performance is one of the automotive industry's primary research areas. Consequently, the study's results can be utilised to optimise engine configurations to achieve maximum performance. The investigation was conducted using a finite volume-based open-source software, OpenFOAM, for computational simulations. Simulations were conducted using the XiEngineFOAM solver with a transport equation for modelling flame fronts. The Standard k-e turbulence model was used to predict turbulence parameters. The simulation was conducted for compression and power stroke (crank angle between - 180° and 180°), assuming an even distribution of the air-fuel mixture within the pentroof 4-valve engine cylinder. Simulations were conducted for four cases, including variations in the position and timing of spark plugs in single-spark and twin-spark engines. According to the results of the simulations, the single-spark engine provides the best performance when the spark plug is ignited early and positioned at the cylinder's centre. When placed at an optimal position determined by flame travel and collision, the twin-spark engine gives the best performance at the highest difference between the spark timings of the two spark plugs.