Semi-global Chemical Kinetic Mechanism for FAME Combustion Modeling

Modeling of combustion engines using computational fluid dynamics (CFD), to investigate and improve performance of biodiesel combustion, calls for development of small and efficient chemical kinetics mechanisms that accurately represent ignition and flame propagation of renewable fuels. In this work, a semi-global approach is used to develop a mechanism suitable for three-dimensional CFD of fatty acid methyl esters (FAME) in compression ignition engines. The mechanism includes five FAME fuel constituents that are the main compounds in FAME fuels such as rapeseed, palm and soybean. Each FAME fuel constituent is modeled using individual fuel breakdown pathways, creating a highly versatile and compact reaction mechanism, capable of modeling any constituent combination and hence almost any FAME fuel blend. The presented mechanism accurately represents the important ignition properties of the fuels and fuel constituents, including the low-temperature chemistry. It is validated against available experimental data as well as a highly detailed reaction mechanism. The presented mechanism offers a unique combination of fuel flexibility, mechanism performance and a low computational cost.