OF THE THESIS Combustion simulation and kinetic modeling using hybrid reduction scheme By JIERUI LIANG Thesis Director: Marianthi G. Ierapetritou Ioannis P. Androulakis Combustion simulation is a promising tool for multi-disciplines such as fuel development, engine design and emission control. Two biggest challenges confronting us include developing a sufficiently detailed kinetic mechanisms of combustion and formulating numerically implementing models that are capable to capture the essentials

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... but computationally affordable. However, combustion simulations using detailed kinetic mechanisms are often prohibitive in computational fluid dynamics (CFD) due to unaffordable computational cost. Thus, the objective of the research is to reduce the computational intensity of detailed kinetic calculations by an on-the-fly/QSSA hybrid mechanism reduction scheme. The work consists of two parts: (i) integrating the hybrid reduction scheme in CRUNCH CFD ® to enable detailed kinetic calculations; and (ii) applying the hybrid reduction scheme to larger kinetic mechanisms like n-pentane and biodiesel surrogate iii methyl butanoate (MB). The models include plug flow reactor (PFR), multi-dimensional engine CFD in KIVA-3V and a supersonic nozzle combustion in CRUNCH CFD ®. A fast flux-based QSS species selection method is also employed to quickly select QSS species for various situations. The efficiency and accuracy of the hybrid reduction have been successfully demonstrated according to our results. Aided by fast QSS species selection, the hybrid reduction scheme is efficient to perform complex combustion simulations accurately using large detailed mechanisms. iv ACKNOWLEDGEMENTS