Assessment of Syngas Kinetic Models for the Prediction of a Turbulent Nonpremixed Flame

We consider eight kinetic models for syngas (CO-H2) oxidation, which have been proposed or used for different applications, such as laminar counter-flow flames and hypersonic engines. The models range in size from 2 global steps to 38 elementary steps. We assess the models performance in predicting a simple turbulent jet flame (Sandia/ETH-Zurich flame A). The fuel consists of CO, H2, and N2 with 40%, 30%, and 30% by volume, respectively. We simulate the turbulent flame using the finite volume method and compare the Favre-averaged profiles of temperature and mass fractions of the stable species with the experimental data. These comparisons characterize the applicability of the kinetic models to turbulent flames. Turbulence is modeled using the k-epsilon model with McGuirk-Rodi modification for round jets. Turbulence-chemistry interaction is modeled using the partially stirred reactor (PaSR) approach. The kinetic models vary largely in their computational cost. Five of the models overpredicted the maximum flame temperature (by 200K-320K). The 2-step (Slavinskaya et al., 2005) and 9-step (Edelman-Fortune, 1969) models underpredicted the maximum temperature by 240K and 580K, respectively. Predictions using the 3-step model of Cuoci et al. (2009), which is based on the Westbrook-Dryer (1981) model for hydrocarbon fuels, gave less than 10K difference. This model also has the lowest computational cost.