Ethanol Lean Combustion Characteristics of a GDI Engine

Abstract

In the present study, ethanol combustion analysis was carried in a wall guided type GDI engine, to achieve combustion stability under lean burn operation and to expand the flammability limit for increasing engine efficiency. Tests were performed at constant engine speed, load and injection pressure (1000 rpm, NIMEP = 3 bar, 100 bar), for a wide range of injection, ignition and mixture formation parameters. NISFC, combustion stability, PMEP and burn duration were evaluated at each excess air ratio. An improvement on fuel economy and, consequently, increased engine efficiency was achieved for excess air ratios of λ = 1.1 and λ = 1.2.