Biodiesel is a promising alternative fuel for compression ignition engines. It is a renewable energy source that can be used in these engines without significant alteration in the design. The detailed chemical kinetics of biodiesel is however highly complex. In the present study, a skeletal mechanism with 123 species and 394 reactions for a tri-component biodiesel surrogate, which consists of methyl decanoate, methyl 9-decenoate and n-heptane, was developed for reduced computational cost in engine simulations. The reduction was based on an improved directed relation graph (DRG) method that is particularly suitable for mechanisms with many isomers, followed by isomer lumping and DRG-aided sensitivity analysis (DRGASA). Error cancelation was employed in obtaining the compact skeletal mechanism with DRGASA. The reduction was performed for pressures from 1 to 100atm and equivalence ratios from 0.5 to 2 for both extinction and ignition applications. The initial temperature for ignition was from 700 to1800K. As such the skeletal mechanism is applicable for both low and high temperature ignition simulations. Compared with the detailed mechanism that consists of 3329 species and 10806 reactions, the skeletal mechanism features a dramatic reduction in size while still retaining good accuracy and comprehensiveness. Additional validation is also performed against liquid length and flame lift-off length data available from Sandia National Laboratories under compression-ignition (CI) engine conditions.
展开▼
