Combustion simulation in a spark ignition engine cylinder: Effects of air-fuel ratio on the combustion duration

• Published in: Thermal science Vol. 14; no. 4; pp. 1001 - 1012
• Main Authors: Dinler, Nureddin, Yucel, Nuri
• Format: Journal Article
• Language: English
• Published: Belgrade Society of Thermal Engineers of Serbia 2010
• Subjects: Aerodynamics; Air-fuel ratio; Combustion efficiency; Computational fluid dynamics; Computer simulation; Contours; Engine cylinders; Finite element method; Finite volume method; Fluid flow; Graphs; Internal combustion engines; Laminar flow; Shape; Spark ignition; Transport equations; Turbulence models; Turbulent flow; Two dimensional flow; Two dimensional models
• ISSN: 0354-9836; 2334-7163
• DOI: 10.2298/TSCI1004001D

Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion equations were solved. The k-e turbulence model was employed. The fuel mass fraction transport equation was used for modeling of the combustion. For this purpose a computational fluid dynamics code was developed by using the finite volume method with FORTRAN programming code. The moving mesh was utilized to simulate the piston motion. The developed code simulates four strokes of engine continuously. In the case of laminar flow combustion, Arrhenius type combustion equations were employed. In the case of turbulent flow combustion, eddy break-up model was employed. Results were given for rich, stoichiometric, and lean mixtures in contour graphs. Contour graphs showed that lean mixture (l = 1.1) has longer combustion duration.