Large Eddy Simulation Studies on Effects of Soot Productivity in a Momentum Dominated Strained Diffusion Jet Flames

Abstract

Abstract The present numerical study is to determine the soot volume fraction, rate of soot nucleation, rate of coagulation, rate of surface growth, and rate of surface oxidation for flame configurations having the fuel mixture composition of C2H4: H2: N2 (63.4: 4.7: 31.9% by mass) along with air. The Brookes–Moss–Hall and OH oxidation radical is coupled with the combustion and P−1 radiation model. The inputs needed for this numerical study to determine soot volume fraction are maintained the same as the earlier experimental conditions. The hyperbolic function in the governing models is interpolated with quadratic upwind interpolation for convective kinetics, diffusion function with second-order upwind in space, and bounded second-order implicit in time. A suitable pressure implicit method for splitting operators, and a pressure–velocity coupler are also incorporated to evaluate pressure to satisfy continuity. The above governing models are solved using the ILU method with a unity Courant–Friedrichs–Lewy number. It is observed that along the axial direction, the flame with 12,900 s−1 shows higher rate of soot nucleation and rate of soot coagulation compared with the flame having lower strain rate. Also, the highest strain rate flame shows the lowest rate of soot surface growth, and also the rate of soot oxidation is the least.