Optimization of port injection of n‐decanol in a PCCI engine using response surface methodology

Abstract

This work aims to define the optimum n‐decanol fraction in the inlet port and the corresponding engine load for the better emissions and performance characteristics of a partially premixed charged compression ignition (PCCI) engine by response surface methodology (RSM). The numerical model based on multi‐linear regression was established using experimental data. For this, the influence of various proportions of n‐decanol through intake port including 10%, 20%, 30%, and 40% were experimentally investigated besides the primary injection of neem oil biodiesel in the volumetric ratio of 80% diesel and 20% neem biodiesel, namely NB20. The optimization using RSM is exploited to capitalize the brake thermal efficiency (BTE) and diminish the emissions including oxides of nitrogen (NOx), carbon monoxide (CO) emission, smoke opacity, and hydrocarbon (HC) emission. The n‐decanol fraction in the port injection of 31.43% and the engine load in terms of brake power of 2.950 kW were found to be optimum parameters with the maximum desirability of 0.752. The optimal responses for brake‐specific fuel consumption (BSFC), BTE, CO, HC, smoke, and NOx under these operating conditions were found to be 0.305 kg/kWh, 28.8%, 0.145%, 19.61%, 54.85 ppm, and 837.7 ppm, respectively. Likewise, the correlation coefficient R2 values for BSFC, BTE, CO, HC, smoke and NOx have been found to be 99.85%, 99.95%, 93.58%, 90.32%, 99.97%, and 99.93%, respectively. According to the study's findings, the RSM is a realistic method for calculating and enhancing a diesel engine's emission and performance values operating in PCCI mode and using n‐decanol and NB20 as fuels.