Increasing the tolerance of spark-ignition engines to high dilution remains a major technical challenge. Existing gasoline flame speed correlations are typically valid over a restricted range of temperatures, pressures and dilutions. However, their determination relies strongly on the accuracy of available chemical kinetic schemes. Increasing dilution by CO₂ and H₂O tends to favor third-order reactions, notably methyl recombination, thereby lowering the system reactivity and increasing the sensitivity of flame speed to reactions involving C₂H_y species. Further, as pressure increases, the flame speed becomes increasingly sensitive to an emerging set of species transport properties.

The proposed approach involves a combination of ab initio electronic structure theory, transition state theory and master equation modelling as well as macrokinetic modelling. Transport coefficients will be evaluated from the Chapman-Enskog theory. The updated detailed thermokinetic and transport database will be evaluated on flame velocities measurements at engine conditions focusing on the ability to reproduce relative variations of flame velocities with pressure, temperature and dilution.

Keywords: quantum chemistry, theoretical kinetics, combustion

For more information or to submit an application, contact the academic supervisor.

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