Numerical investigation of nitrogen oxides emission from turbulent non-premixed flames
Nitrogen oxides emission from a series of turbulent me thane jet non-premixed flames with different Reynolds number was numerically si mulated, in order to investigate the influence of turbulence on the formation of nitrogen oxides.A two-scale k-e turbulence model was adopted to calculat e turbulent velocity field, and the probability density function (PDF) method wa s combined with the Lagrangian flamelet model to predict the turbulent scalar fi elds.Detailed chemical reaction mechanism GRI-Mech 3.0 was incorporated to des cribe methane oxidation and nitrogen oxides formation.The comparisons between ni trogen oxides predictions and measurements were made,and the influence of Reynol ds number, scalar dissipation and flamelet time on the formation of nitrogen oxi des was discussed. The numerical results were in good agreement with the measure ments, and the trend that nitrogen oxides emission decreased with the increase o f Reynolds number in the experiment was reasonably represented by the present nu merical models.