Mehdi Bidabadi - School of Mechanical Engineering Department of Energy Conversion, Iran University of Science and Technology, Combustion Research Laboratory
Hossein Beidaghy Dizaji - School of Mechanical Engineering Department of Aerospace Engineering, Iran University of Science and Technology, Combustion Research Laboratory
Mohammadreza Khodadadi Dizaji - School of Mechanical Engineering, Azad University of Tabriz

A computer model has been developed for the analysis of confined, axis-symmetric, turbulent diffusion flames in a burner element due to high temperature and velocity gradients in the combustion chamber. The conservation equations of mass, momentum, species and energy in the turbulent flow field were solved in conjunction with the RNG k–ε turbulence model. In this case, the standard eddy dissipation is used as the turbulent combustion model and for subsequent nitrogen oxide predictions. A post-processing NO formation model was used to predict the concentration of thermal and prompt NO. The combustion model is based on reactions limited by mixing rate local chemical equilibrium. A model is presented for the rate of combustion which takes into account the intermittent appearance of reacting species in turbulent flames. This model relates the rate of combustion to the rate of dissipation of eddies and expresses the rate of reaction by the mean concentration of reacting specie, the turbulent kinetic energy and the rate of dissipation of this energy. The effects of equivalence ratio (φ) and oxygen percentage (γ) in the combustion air and NO formation are investigated for different values of φ and γ.

Combustion, Turbulence, Eddy dissipation model, Computer Fluid Dynamics