Optimum engine operating parameters on VCR engine performance and emission analysis is a challenging scenario towards the stringent emission control policies adopted by the globe. The engine operating parameters such as compression ratio (CR), fuel blends and fuel injection pressure (FIP) were implemented on VCR engine to improve its performance and to control its gaseous emissions. The input variable were chosen as FIP (185 bar,205 bar &225 bar), CR (18:1,19:1,20:1,21:1 & 22:1) and fuel blends (B20 & diesel) as parameters for designing the experiments using DoE. The predicted mathematical model was recognized by p-test and R² value using RSM approach to find optimum CR and FIP of biodiesel blend in comparison with standard diesel. The responses such as maximum rise in in-cylinder pressure, exhaust gas temperature, HRR, BTE, SFC and various gas emissions of CO, HC, CO₂ and NO_x on VCR engine analysis were predicted. The optimized engine characteristics such as combustion and emissions were improved with CR21, FIP 225 bar of 20% biodiesel blends in comprehend with neat diesel in detailed experimental investigation at a load of 0.46 MPa of BMEP with a constant speed of 1500 rpm. The superior BTE with lower SFC was attained through a FIP of 225 bar and on CR 21 compared with that of diesel and other fuel injection pressures. The carbon monoxide and hydrocarbon emission were reduced substantially at 225 bar injection pressure and on CR 21. The acceptable limits CO₂ and NO_x emission are observed and compared with neat diesel with a FIP of 225 bar and on CR 21.

在全球范围内采用严格的排放控制政策方面，在VCR发动机性能和排放分析方面的最佳发动机运行参数是具有挑战性的方案。在VCR发动机上采用了诸如压缩比（CR），混合燃料和燃料喷射压力（FIP）之类的发动机运行参数，以改善其性能并控制其气体排放。输入变量选择为FIP（185 bar，205 bar和225 bar），CR（18：1,19：1,20：1,21：1＆22：1）和混合燃料（B20和柴油）作为参数使用能源部设计实验。预测的数学模型通过p检验和R ²识别与标准柴油相比，使用RSM方法可找到最佳的生物柴油混合物CR和FIP值。诸如缸内压力的最大升高，废气温度，HRR，BTE，SFC以及各种CO，HC，CO ₂和NO _x的气体排放等响应对VCR引擎的分析进行了预测。在详细的实验研究中，在0.46 MPa的BMEP负载和1500 rpm的恒定负载下，使用CR21，FIP 225 bar的20％生物柴油混合物和纯柴油，改善了发动机的最佳性能，例如燃烧和排放。与柴油和其他燃料喷射压力相比，通过225 bar的FIP和CR 21获得了具有较低SFC的出色BTE。在225 bar的注射压力和CR 21下，一氧化碳和碳氢化合物的排放量显着降低。观察到可接受的极限CO ₂和NO _x排放，并与FIP为225 bar的纯柴油和CR 21进行了比较。