Experimental and numerical findings on VCR engine performance analysis on high FFA RSO biodiesel as fuel using RSM approach

Abstract

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 NOx 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 NOx emission are observed and compared with neat diesel with a FIP of 225 bar and on CR 21.