Evaporation and mixture formation of gasoline–ethanol sprays in spark ignition engines with pre-blended injection and dual injection: a comparative study

• Published in: IET renewable power generation Vol. 13; no. 4; pp. 539 - 548
• Main Authors: Van Ga, Bui, Van Nam, Tran, Quang Trung, Nguyen, Tan Tien, Huynh
• Format: Journal Article
• Language: English
• Published: The Institution of Engineering and Technology 18.03.2019
• Subjects: compression process; double‐inlet manifolds; dual injection system; evaporation; evaporation rate; fuel systems; ignition; internal combustion engines; mixture formation; numerical analysis; numerical simulation; organic compounds; petroleum; port injection; preblended gasoline–ethanol mixture; pure gasoline; Research Article; separate injection system; separation; single‐inlet manifold; spark ignition engine; sprays; vapour concentration; mixture formation; spark ignition engine; fuel systems; dual injection system; single-inlet manifold; double-inlet manifolds; evaporation rate; internal combustion engines; separation; port injection; vapour concentration; separate injection system; pure gasoline; numerical analysis; preblended gasoline–ethanol mixture; sprays; organic compounds; petroleum; evaporation; ignition; compression process; numerical simulation
• ISSN: 1752-1416; 1752-1424; 1752-1424
• DOI: 10.1049/iet-rpg.2018.5106

Evaporation of sprays and mixture formation as injection of pre-blended gasoline–ethanol mixture and as separate injection of the fuels are investigated by means of numerical simulation. Effects of operating conditions and different configurations of injection systems have been examined. Under the same operating conditions, pure gasoline mostly evaporated during the injection period, while pure ethanol evaporated mainly during the compression process. Charge temperature in the cylinder for pure ethanol is ∼60°C lower than that for pure gasoline at the end of the compression process. Independently from injection system, the dual injection results in a higher evaporation rate compared to pre-blended injection. Whether pre-blended injection or dual injection is employed, the evaporation rate is improved for port injection (PI) compared to direct injection (DI). Besides, vapour concentration at the end of the compression process of PI increases with a shift from a single-inlet manifold to double-inlet manifolds. Mixture homogeneity is enhanced with increasing ambience temperature or/and an increasing engine speed with pre-blended injection, while a strong stratified charge mixture is achieved with dual injection using double-inlet manifolds or with DI of ethanol combined with PI of gasoline.