This thesis aims at extending combustion theory with detailed kinetics in three directions, namely: Part I theoretically analyzes the explosion limits of homogenous mixtures; Part II investigate the effect of low-temperature chemistry (LTC) in autoignition, flame and detonations; and Part III explores several problem regarding accurate measurements and modellingof laminar flame speeds.;In Part I, the canonical explosion limits of hydrogen-oxygen mixtures are first theoretically analyzed. The present theory extends previous linear analysis with the participation of radicalradical reactions. Subsequently, the role of hydrogen addition to the explosion limits of carbon monoxide-oxygen and methane-oxygen mixtures has been evaluated. Eigenvalue analysis shows that carbon monoxide-oxygen mixtures are more sensitive to hydrogen addition. However, the methane-oxygen mixtures show mild monotonic-to-nonmonotonic transition with respect to hydrogen addition.;Part II investigates the role of LTC in autoignition and combustion waves. It first discusses the LTC affected two-stage autoignition with emphasis on the LTC-controlled first-stage ignition. Then, the role of LTC in the two canonical combustion waves, namely subsonic deflagration and supersonic detonation, are examined respectively. For the LTC-affected deflagration, the cool flame propagation is achieved through the planar flame near flammability limit with heat loss. The extended flammability limits with cool flames are theoretical predicted by the related LTC kinetic pathways. For the LTC-affected detonation, the ZND structure at highly diluted conditions exhibits two distinct stages of energy release caused b low- and high-temperature chemistries, respectively. Based on the ZND structure, the dynamic parameters of the cell size, direct initiation energy and critical tube diameter of detonation within the LTC affected regime are discussed.;Part III examines several problems on laminar flame propagation. First, the role of finite flame thickness in the extrapolation of laminar flame speed from expanding spherical flame is investigated. A new extrapolation expression allowing for finite flame thickness is proposed. Next, the supercritical effect on laminar flame speed at high pressures is studied. By progressively incorporating the real fluid models into the simulations, contributions of each component are assessed and elucidated. Finally, the role of Soret diffusion on the flame propagation and initiation is numerically probed.
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