To achieve emission standard norms and higher fuel efficiency conversion are the main concerns in diesel engines. The single parametric study approach might not attain the optimal combustion characteristics. In order to overcome this issue, multi objective study has been carried out to achieve the higher performance and simultaneously reduction of emissions. The main objective of present article is identifying the optimum set of the engine parameters for diesel fuel, which gives better performance and emissions. Numerical analysis was carried out by using CONVERGE CFD software. Numerical analysis were carried out by varying the Compression Ratio (CR) (12–16.5), Start of Injection (SOI) (0–25° bTDC), Fuel Injection Pressure (FIP) (500–1,400), and Exhaust Gas Recirculation (EGR) (0–40%). Response surface methodology was used for optimization. The parameters are optimized for minimizing the NO_x, soot, and ISFC by using the Response Surface Methodology (RSM). Regression equations were developed for the responses such as ISFC, NO_x, and soot. It was observed that the interaction effects also play a major role in determining the performance and emission characteristics of the engine. The optimum combination of operating parameters was found to be CR 14.55, SOI 16.29° bTDC, FIP 855 bar, and EGR 26.15% with a composite desirability of 0.94. The corresponding NO_x and soot emissions are reduced by 40.3% and 52.38%, respectively, and a marginal reduction in the ISFC is accomplished. Mixture homogeneity (TFDI) was improved 27% for optimum case compared to baseline configuration.

中文翻译：

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直喷CI发动机的参数优化以改善燃烧特性

为了达到排放标准规范和更高的燃油效率转换是柴油发动机的主要关注点。单参数研究方法可能无法获得最佳燃烧特性。为了克服这个问题，已经进行了多目标研究以实现更高的性能并同时减少排放。本文的主要目的是确定柴油发动机参数的最佳设置，以提供更好的性能和排放。使用CONVERGE CFD软件进行了数值分析。通过改变压缩比（CR）（12–16.5），喷射开始（SOI）（0–25°bTDC），燃料喷射压力（FIP）（500–1,400）和废气再循环（ EGR）（0–40％）。响应面方法用于优化。_x，烟灰和ISFC，方法是使用响应面方法（RSM）。针对诸如ISFC，NO _x和烟灰之类的响应，建立了回归方程。据观察，相互作用效应在确定发动机的性能和排放特性方面也起着重要作用。发现运行参数的最佳组合为CR 14.55，SOI 16.29°bTDC，FIP 855 bar和EGR 26.15％，综合期望值为0.94。相应的NO _X，并通过分别40.3％和52.38％，降低碳烟排放，并在ISFC边际降低来实现的。与基准配置相比，最佳情况下的混合物均质性（TFDI）提高了27％。