Simultaneous control of NO_x and smoke emission of compression ignition engine was the major challenge for the researchers as their formation mechanisms are inversely proportional to each other. In the present study, combustion process was modified as partially premixed charge combustion (PPCC) which supplies a premixed charge of fuel and air through inlet valve in addition to the fuel injected into the cylinder. This resulted in reduction of combustion temperature with lean air fuel ratio. To investigate the influence of various factors on these emissions, six design factors and two fuel factors of the engine were selected as factors and NO_x, smoke, and brake thermal efficiency were selected as responses for the investigation. Experimental test matrix was designed based on Taguchi L₁₈ orthogonal array. Multi response Signal to Noise (MRSN) ratio was calculated for the response variables and the optimum combination level of factors was obtained simultaneously using Taguchi's parametric design and the same was tested experimentally. Influence of each factor and most influencing factor on the chosen objective was determined by analyzing the variance of the MRSN ratio. This investigation reveals that among the factors tested, main injection fuel is the most influencing factor with a maximum percentage contribution of 44.5. It has been observed that normal combustion mode parameters have more influence with a percentage of contribution of 80 when compared with the parameters of PPCC mode. It has also been observed that fuel factors have higher percentage contribution of 53 compared with the design factors contribution of 43.6.

中文翻译：

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基于田口的生物柴油和丁醇混合燃料部分预混充量 CI 发动机设计和燃料参数优化

同时控制压燃式发动机的 NO _x和烟雾排放是研究人员面临的主要挑战，因为它们的形成机制彼此成反比。在本研究中，燃烧过程被修改为部分预混充量燃烧 (PPCC)，除了喷射到气缸中的燃料外，它还通过进气阀提供燃料和空气的预混充量。这导致以稀空燃比降低燃烧温度。为了研究对这些排放物的各种因素的影响，六个设计因素以及发动机的两个燃料因素被选定为因子和NO _X，烟雾和制动热效率被选择为用于调查响应。基于Taguchi L设计的实验测试矩阵₁₈正交阵列。计算响应变量的多响应信噪比 (MRSN)，同时使用田口的参数设计获得最佳的因子组合水平，并通过实验对其进行测试。通过分析MRSN比的方差，确定每个因素和影响最大的因素对所选目标的影响。该调查表明，在测试的因素中，主喷射燃料是影响最大的因素，贡献百分比最大为 44.5。已经观察到，与 PPCC 模式参数相比，正常燃烧模式参数具有更大的影响，贡献百分比为 80。还观察到，与设计因子贡献的 43.6 相比，燃料因子的贡献百分比更高，为 53。