Estimation of double-Wiebe function parameters using least square method for burn durations of ethanol-gasoline blends in spark ignition engine over variable compression ratios and EGR levels

摘要: Abstract Phasing and duration are two of the most important aspects combustion in Spark Ignition (SI) engines. They impact efficiency, emissions, overall engine performance. These can be represented by mass fraction burn (MFB) profile. Having an accurate mathematical model MFB profile leads to ability process and, thus, properly 1D simulation tools. The Wiebe function is widely used estimate as a crankshaft position. In this work, for purpose validating sub-process, parameters were calculated using analytical solution least squares method fitting locations, determined from analysis measured cylinder pressure, both single double-Wiebe functions. To determine accuracy respective function, single-zone pressure was applied reconstruct trace. Once trace recovered, reconstructed then compared with experimentally Results showed that fit better than single-Wiebe model. root mean square error (RMSE) estimation 7.9 kPa. comparison, RMSEs traces methods 70.0 kPa 75.9 kPa, respectively, demonstrating significant improvement.