Reduced Mechanism Approach of Modeling Premixed Propane-Air Mixture using Ansys Fluent

Abstract

In computational analysis of combustion, reduced mechanisms are often used in place of detailed kinetic chemistry because the computational costs of including all the species in the reactor model are always prohibitively high; for this reason, many different reduced mechanisms have been developed for hydrocarbon oxidation. In this study we employed ANSYS Fluent Computational Fluid Dynamics (CFD) package, (hereinafter referred to as Fluent) to analyze propane oxidation mechanism in a conical reactor. The model employed for this work is based on the results of Westbrook and Dryer [15]. This simplified model consists of 5 chemical reactions and 12 species, namely, C₃H₈, CO₂, CO, H₂O, NO, O₂, O, H, N, OH, N₂ and H₂. The computed mass fractions of the species, C₃H₈, CO₂, CO and H₂O were found to be in qualitative agreement with measured values presented in [26]. The results of the present study show that the bulk of the turbulent kinetic was produced in the inlet jet. The turbulent viscosity was found to be an excellent â€mixer†of the species. The computed results of y* were found to confirm that the use of the law-of-the-wall functions was valid and it also showed that the computational mesh used was adequate for resolving the flow dynamics in the near wall region.