A novel approach for experimental study and numerical modeling of combustion characteristics of a hydrogen fuelled spark ignition engine

Abstract

This work is aimed for experimental study on effects of spark timings, compression ratios (4.5:1 to 7.2:1) and exhaust gas recirculation (EGR) on combustion characteristics of hydrogen fuelled spark ignition (SI) engine operating at 3000 rpm. The results indicate spark timing should be reduced for hydrogen fuelled engine as compared to the gasoline fuelled engine. Both ignition lag and DOC decreased with an increase in equivalence ratio and compression ratio, while the opposite trend was observed with an increase in EGR. The EGR was limited up to 23.5 % by volume, as higher EGR lead to cyclic variation. The standard Wiebe function constants were modified for the calculation of mass fraction burnt in a hydrogen fuelled SI engine. In addition to this, the empirical correlations were developed for ignition lag (IL) and duration of combustion (DOC) as a function of compression ratio, equivalence ratio, and EGR. The notable findings that emerged from this study are that hydrogen-fuelled SI engines should be operated at varying spark timing with respect to varying equivalence ratios (0.5 to 0.8) and EGR up to 23.5% by volume.