CFD analysis of turbulent flow characteristics of charge inside the combustion chamber of a dual–fuel homogeneous charge compression ignition engine under varying swirl ratios

Abstract

This paper discusses the effects of the swirl ratio on the distribution of turbulent kinetic energy (TKE), combustion and emissions characteristics of a dual-fuel HCCI (Homogeneous charge compression ignition) engine fed with n-dodecane (premixed) and ethanol (injection). The performance of the Internal combustion (IC) engine is investigated using STAR-CD. ECFM-3Z (Extended Coherent Flame Combustion Model-3Zones) model is considered for the computational fluid dynamics (CFD) simulations. This study also includes the influence of swirl ratio on pressure and temperature of the combustion and hence the NOx (Nitrogen oxides), soot and CO2 (Carbon dioxide) emissions. The pressure, temperature and emissions of the combustion have been dropped significantly by increasing the swirl ratio. There is an increase in the distribution of air-fuel and hence the corresponding combustion flame by increasing the swirl ratio. It is observed that the reduced emissions of the combustion were achieved in the case of swirl ratio 3 and the values of the NOx emission, soot and CO2 emission are 0.0024 g/kg fuel, 0.0022 g/kg fuel and 5.12 g/kg fuel respectively. Eventually, the paper deals with the significance of the swirl ratio on NOx and CO2 emissions with limited loss of the piston work.