Recent development of biodiesel combustion strategies and modelling for compression ignition engines

Abstract

The combustion phenomena of biodiesel and its blends are not the same as fossil diesel combustion in compression ignition (CI) engines due to their different physio-chemical fuel properties. The combustion of biodiesels is just like the combustion of fossil diesel which emits toxic gases such as nitric oxides (NOx) and particulate matter (PM), CO, HC etc. The paper has been critically reviewed the recently developed combustion strategies for biodiesel combustion in CI engine. Low temperature combustion (LTC) is one of the recently developed strategies that have three different categories, namely homogeneous charge, premixed charge and reactive controlled compression ignition which have been briefly discussed here. The study identified that LTC strategy can significantly reduce PM and NOx emission by combustion of biodiesel. However, CO and HC emission increases due to higher rate of exhaust gas recirculation (EGR). It also identified that CI engine produces lower break thermal efficiency and higher break specific fuel consumption (BSFC) under LTC combustion strategies. A good predictive combustion model can help to address all these drawbacks in LTC strategy. The study concluded that a hybrid k-ε and k-ω turbulent model namely, shear-stress transport (SST) k-ω turbulence combustion model can help to predict more efficient combustion of biodiesel in CI engines under LTC strategy. These combinations are capable of improving engine efficiency by limiting harmful emissions of biodiesel combustion in CI engine.