Gasoline Combustion Chemistry in a Jet Stirred Reactor

  • Bingjie Chen

Student thesis: Doctoral Thesis

Abstract

Pollutant control and efficiency improvement propel the need for clean combustion research on internal combustion engines. To design cleaner fuels for advanced combustion engines, gasoline combustion chemistry must be both understood and developed. A comprehensive examination of gasoline combustion chemistry in a jet stirred reactor is introduced in this dissertation. Real gasoline fuels have thousands of hydrocarbon components, which complicate numerical simulation. To mimic the behavior of real gasoline fuels, surrogates, composed of a few hydrocarbon components, are offered as a viable approach. In this dissertation, combustion chemistry of n-heptane, a key surrogate component, is investigated first, followed by an evaluation of a surrogate kinetic model. Finally, real gasoline fuels are assessed with the surrogate kinetic model. Mass spectrometry was employed to measure intermediates in n-heptane low temperature chemistry. Reaction pathways of the observed intermediates were proposed and clarified. n-Heptane low temperature oxidation reaction scheme was expanded by the proposed reactions. After surrogate proposal and formation, a surrogate kinetic model was examined. Low temperature and high temperature chemistry were observed and predicted. The octane number and composition effect on low temperature oxidation reactivity were revealed. High temperature combustion chemistry was found to be similar among the different surrogates, and the surrogate kinetic model reproduced surrogate behavior well in both low and high temperatures. Finally, the proposed surrogate model was examined using real gasoline fuels. Five real FACE (fuel for advanced combustion engines) gasolines were selected as target fuels to cover a wide range of octane number, sensitivity and hydrocarbon compositions. Low temperature oxidation chemistry was investigated for two intermediate octane number gasolines, FACE A and C. For a high octane number gasoline, FACE F, key pollutant production pathways were the focus of high temperature combustion chemistry. Two low octane number gasolines, FACE I and J, were compared with three other FACE gasolines to clarify gasoline combustion chemistry over a wide range. The gasoline surrogate chemical kinetic model proved to be a comprehensive, viable, accurate and powerful approach for numerical simulations. The proposed gasoline surrogate chemical kinetic model can aid in the numerical design of advanced combustion engines.
Date of AwardMar 2019
Original languageEnglish (US)
Awarding Institution
  • Physical Science and Engineering
SupervisorMani Sarathy (Supervisor)

Keywords

  • Gasoline, Combustion Chemistry, Surrogate, n-heptane, kinectic model, jet stirred reactor

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