Development of an ethanol reduced kinetic mechanism based on the quasi-steady state assumption and feasibility evaluation for multi-dimensional flame analysis

A 20-step reduced kinetic mechanism of ethanol, a potential sustainable energy source as a biofuel, was developed based on the detailed reaction mechanism proposed by Saxena and Williams using the Computational Singular Perturbation (CSP) method based on the Quasi-steady State Assumption (QSSA). Feasibility evaluation of the reduced kinetic mechanism for multi-dimensional flame analysis, i.e., the difference in numerical results and convergence time between the detailed reaction mechanism and the reduced kinetic mechanism, was also performed to investigate the applicability of the ethanol reduced kinetic mechanism to the development of practical combustors. To consider further industrial applications,the reduced kinetic mechanism was incorporated into the commercial computational fluid dynamics (CFD) code FLUENT 6.3.26 using the User Defined Function (UDF) code developed in the present study. Numerical results calculated with the detailed reaction mechanism and the reduced kinetic mechanism, i.e., temperature profiles, chemical species profiles and laminar burning velocities, were in good agreement for both two-dimensional premixed and non-premixed flame calculations. Convergence time using the reduced kinetic mechanism was considerably reduced compared to that using the detailed reaction mechanism, indicating the applicability and advantage of a reduced kinetic mechanism based on QSSA for multi-dimensional flame analysis. An additional reduction of the computational time was achieved by using both the reduced kinetic mechanism and In Situ Adaptive Tabulation (ISAT) solver by Pope et al.