Flex-fuel engine: Influence of ethanol content on power and efficiencies

Abstract

Gasoline is a complex mixture of different hydrocarbons, with a wide spectrum of constituents. Surrogate fuels have a reduced number of chemical components and therefore are used to model commercial fuels and enhance the understanding of fuel behavior in internal combustion engines. Surrogates also allow better fuel property control. In previous work, a surrogate fuel blend of iso-octane, n-heptane, toluene and ethanol was found to be suitable for commercial, high-octane, oxygenated Brazilian gasoline. This article investigates the influence on a Flex-fuel engine power and efficiencies of different ethanol levels in this surrogate fuel blend. The study found some different trends when comparing to other works in the literature. This article intends to make contributions presenting more detailed analyses of how fuel properties can influence several Flex-fuel engine performance parameters.

Critical review on recent progress of ethanol fuelled flex‐fuel engine characteristics

“…87,108 Whereas, the ID and CD are decreased with the addition of ethanol due to chemical and physical reaction of air-fuel mixture with higher laminar flame speed. 88 The ID and CD are increased for ethanol combustion at lower load conditions and it shows opposite trends at higher loads. 109 In contrast to CP, the CT decreases with an increase of ethanol fraction in air-fuel mixture due to higher LHV of ethanol, causing charge cooling effect and minimizing the combustion temperature.…”

“…Attainment of peak HRR and quantity of MFB are advanced to the crank angle for ethanol due to the faster‐burning capability of ethanol 87,108 . Whereas, the ID and CD are decreased with the addition of ethanol due to chemical and physical reaction of air‐fuel mixture with higher laminar flame speed 88 . The ID and CD are increased for ethanol combustion at lower load conditions and it shows opposite trends at higher loads 109 .…”

“…In the case of FFE, it is decreased with the increase of ethanol share, on account of ethanol injection in the intake manifold or port or in‐cylinder does not significantly impact on charge cooling. However, the fuel vapour produced from the injected surplus ethanol fuel occupies a larger volume to maintain the stoichiometric air‐fuel operating condition and results in poor volumetric efficiency 88 …”

“…However, the fuel vapour produced from the injected surplus ethanol fuel occupies a larger volume to maintain the stoichiometric air-fuel operating condition and results in poor volumetric efficiency. 88…”

Turbocharged spark-ignition engine performance prediction in various inlet charged air temperatures fueled with gasoline–ethanol blends

“…Masum et al 15 studied the effects of different gasoline–ethanol blend mixtures on the fuel properties, the performance and the emissions of an SI engine. Machado et al 16 investigated the influence of ethanol content on power and efficiencies on a flex-fuel engine. Iodice et al 4 studied on the advantages of ethanol–gasoline blends as fuel substitute for last generation SI engines.…”