No. 124, 2012, 81-91

On proper closures for modeling of turbulent Combustion


The subject of this work is the numerical simulation of a turbulent diffusion jet flame fueled with a mixture of CH4, h2 and N2. Simulations have been investigated with various two-equation turbulence models to improve prediction of jet flow fields. The calculations are validated against existing experimental data obtained by Roman and laser Doppler velocimetry. In particular, a comparison of three two-equation turbulence models and their influence on combustion process is presented, namely the Pope corrected k-ε model, standard k-ε model, and the reliable k-ε. For combustion modeling the eddy dissipation concept (EDC) model with a 25-step reaction is considered. The numerical results for mean velocity components, temperature, and major chemical species are presented and compared with the experimental data. The goal of the work is to investigate the capabilities of the used turbulence models in proper predicting of the round jet spreading in a nonpremixed jet flame. Simple geometry allows for relaible flow simulations. Calculations were performed usinf FLUENT 2D and 3D solver. The Pope correction has been applied via the user defined funtions. The advantages and disadvantages of the models are discussed in detail in the meantime during presentation of the results.


two-equation turbulence, jet flows, pope correction, combustion