Evolution of the soot particle size distribution in a turbulent nonpremixed bluff body flame*

The new Bivariate Multi-Moment Sectional Method (BMMSM) has recently shown its potential of tracking the evolution of the soot size distribution in Large Eddy Simulation (LES) of a turbulent nonpremixed jet flame. BMMSM characterizes the soot size distribution by considering soot sections and three volume-surface moments per section, which accounts for soot's fractal aggregate morphology. BMMSM is as accurate as but requires fewer degrees of freedom compared to traditional sectional methods. In this work, BMMSM is used to investigate the evolution of the soot size distribution in a turbulent nonpremixed bluff body flame, which is characterized by very different time-temperature-composition histories compared to a jet flame. Global soot quantities are first validated against experiments and compared against previous computations using a moment method. The evolution of the soot distribution is then analyzed in detail and used to reveal the underlying mechanisms. Additionally, computational considerations of BMMSM will be discussed.