Multi‐objective optimization of performance and emission characteristics of a diesel engine fueled with green ternary blends

This study investigates the performance and emission characteristics of a diesel engine powered with a ternary fuel blend (diesel/cottonseed biodiesel/n‐butanol) at different operating conditions. Experiments were conducted as per the L 35 orthogonal array at the set of three different parameters (engine load, fuel type, and injection timing), and engine responses were recorded. Furthermore, quadratic regression models were developed for all engine responses and analyzed through RSM and statistically validated through ANOVA. The ANOVA result indicates that load was the most significant factor influencing performance and emission response. Experimental analysis finds that the blending of biodiesel/n‐butanol in diesel reduced CO and HC emissions by 22% and 18%, respectively. However, the NO x emissions increased by ~12% when compared to baseline diesel fuel. Multi‐objective optimization using the desirability approach found optimum operating conditions at 77.9% load, fuel type 4 (D55‐CSB30‐Bu15), and a fuel injection timing (FIT) of 23°bTDC. Under these optimized conditions, the engine delivered BTE of 28.2%, BSFC of 0.292 kg/kWh, CO of 0.035%, CO 2 of 1.98%, HC of 13.9 ppm, and NO x of 811 ppm, with an overall desirability value of 0.64. The engine was further operated at the optimum set of input combinations for experimental validation. The result shows that the maximum error between RSM predicted and experimental was below 6%.