Effect of compression ratio on performance, combustion and emissions characteristics of compression ignition engine fueled with jojoba methyl ester

The major challenges facing the energy sector are the cost of fossil fuel and its depletion. Therefore, the current work presents an experimental investigation on the effect of different blends of jojoba methyl ester (JME) in diesel engine performance, combustion and emissions characteristics. A numerical investigation on the effect of compression ratio (CR) on using neat JME is also presented. Thermophysical properties of JME and raw jojoba oil are measured and characterized by FT-IR and GC-MS analysis. Engine performance parameters, combustion characteristics and emission characteristics are measured for single cylinder, four-stroke, direct injection diesel engine fueled with diesel and different blends of JME in diesel (5%, 10%, and 20% by volume). A comprehensive numerical setup using ANSYS FORTE code is developed and validated against new measurements. Results illustrated that by increasing CR from 18 to 23 the peak incylinder pressure is increased considerably. Additionally, increasing CR leads to higher NOx and CO, UHC concentrations for diesel and JME100. The reduction in peak in-cylinder pressure resulting from using JME100 instead of diesel could be recovered by increasing CR from 21.5 to 23. This highlights the possibility of using neat JME in compression ignition engines with less emissions and minimal losses in the output power.