Studies on the flame dynamics and kinetics of alcohols and liquid hydrocarbon fuels.

摘要

An experimental and numerical study was conducted on the propagation and ignition and extinction limits of alcohols and liquid hydrocarbon fuels. Experimentally, the extinction and/or ignition limits were determined for a wide range of fuels including: C1-C2 alcohols, C 5-C14 n-alkanes, C8 iso-alkanes, samples of gasoline, gasoline surrogates, samples of jet fuels, jet fuel surrogates, and synthetic fuels. Experiments were conducted for both premixed and non-premixed flames, and at ambient as well as elevated temperature. Comparison between the ignition and extinction limits of flames involving the various fuels provided insight into their burning characteristics, their relative performance, and the effect of chemical classification. The insight that was gained will aid in future surrogate development work and will provide direction for the desired composition of practical fuels. Numerically, selected experiments were simulated utilizing quasi-one-dimensional codes, which integrate the conservation equations of mass, momentum, energy, and species with detailed descriptions of molecular transport and chemical kinetics and by invoking a variety of chemical kinetic mechanisms. Through comparison between the numerical simulations and experimental results the adequacy and applicability of existing chemical kinetic mechanisms was assessed. Insight was gained into the fundamental kinetic and transport mechanisms that control flame phenomena of interest. Additionally, the inadequacies in current standard chemical kinetic mechanisms optimization practices were identified, namely the exclusion of flame phenomena other than propagation as a constraint, and the exclusion of transport properties as parameters.