On the Suitability of Turbulence Models for the Prediction of Velocity and Temperature Distributions in Methane Non-Premixed Flame

Abstract

This study focuses on the investigation of the suitability of turbulence models on the predictions of flow field and reactive scalars (temperature and species) of a turbulent non-premixed flame. Turbulence models tested in this study included: the standard k-ε, RNG k-ε, standard k-ω, SST k-ω (Shear Stress Transport) and the Reynolds Stress Model (RSM). For the sake of ease and simplicity, Eddy Dissipation combustion model (EDM) was used to predict the temperature fields and species concentrations in the flame. Predictions generated by different turbulence models are then validated against experimental data from a turbulent methane-air flame called flame A. Experimental data of flame A provides information on flow field (velocity) and reactive scalars (temperature and species concentrations). Results of the investigation showed that among five turbulence models tested, the standard k-ε model provides the predictions that are in closer agreement to the experimental data of flow field, temperature, and species concentrations. In general, it can be concluded that apart from the standard k-ε model, other turbulence models are not capable of capturing the position and the value of peak temperature accurately. On the other hand, the standard k-ε turbulence model is able to accurately predict the position and the value of peak temperature in the flame. This is attributed to a better prediction of the flow field by the standard k-ε turbulence model than those of other turbulence models. These findings indicate that the standard k-ε turbulence model in combination with Eddy dissipation combustion model is capable of producing accurate predictions of flame flow field and temperature.