DYNAMIC MODELING OF SOOT PARTICLE COAGULATION AND AGGREGATION - IMPLEMENTATION WITH THE METHOD OF MOMENTS AND APPLICATION TO HIGH-PRESSURE LAMINAR PREMIXED FLAMES

The method of moments was extended to include a more complete descript ion of particle coagulation, namely, the transition and continuum regi mes as well as the formation and growth of fractal aggregates. The for malism preserves the numerical efficiency and the physical rigor of th e method of moments by inclusion of just two additional moment equatio ns and without prescribing a mathematical form to the particle size di stribution function. The extended model was used to simulate soot form ation in several 10 bar laminar premixed ethylene-air flames. The resu lts demonstrate that the more complete formulation improves significan tly model prediction of experimental data, thereby explaining the appe arance of a catastrophic decrease in coagulation rates, which could no t be rationalized within the classical theory of Brownian coagulation. (C) 1998 by The Combustion Institute.