Experimental investigation of engine characteristics of CI engine fueled with fatty acid Millettia Pinnata oil with non‐fatty acid Pinus oil blended fuel

This article studied the effect of blending low‐viscous Pinus oil with high‐viscous Millettia Pinnata oil on CI engine characteristics. The three blends of a combination of Pinus oil and Millettia Pinnata oil (P70K30, P50K50, and P30K70) were tested in a single‐cylinder water‐cooled computerized diesel engine coupled with an eddy current dynamometer by varying the load from 0% to 100%. The performance result establishes a positive correlation between BTE and the amount of Pinus oil in the blended fuel. Among the tested biofuel samples, P70K30 has the highest brake thermal efficiency of 29.73% but is 4.8% lower than diesel. At full load, the BSFC and BSEC of P70K30 show a 7.4% and 8.6% drop compared to diesel fuel but are higher than P50K50 and P30K70. Among the tested biofuel samples, a maximum in‐cylinder pressure of 70.96 bar was observed for P70K30, which is higher than P50K50 and P30K70 but lower than diesel. The net heat release rate and rate of pressure rise were found to be 48.26 J/oCA and 5.57 bar/oCA for P70K30, the highest among all tested conditions. Cycle‐to‐cycle variations were studied by calculating the standard deviation, range, and coefficient of variation for the in‐cylinder peak pressure of 100 cycles. The P70K30 has a coefficient of variation of 1.24%, which is higher than the P50K50 and P30K70 but lower than diesel. The P‐v diagram concludes that the three tested biofuels have strong thermodynamic properties since they have a good expansion rate and a pattern similar to diesel fuel. The emissions results show that increasing the amount of Pinus oil in blended fuel increases the NOx to 1410 ppm emissions and decreases the CO to 0.18%, HC to 44 ppm, and smoke to 76.6%.