Technical Report 39, c4e-Preprint Series, Cambridge

Coupling a stochastic soot population balance to gas-phase chemistry using operator splitting

ref: Technical Report 39, c4e-Preprint Series, Cambridge

Associated Themes: Numerics and Nanoparticles

Abstract

The feasibility of coupling a stochastic soot algorithm to a deterministic gas-phase chemistry solver is investigated for homogeneous combusting systems. A second order splitting technique was used to decouple the particle population and gasphase in order to solve. A numerical convergence study is presented which demonstrates convergence with splitting step size and particle count for a batch reactor and a perfectly stirred reactor (PSR). Simulation results are presented alongside experimental data for a plug flow reactor (PFR) and a comparison to a method of moments simulation of a perfectly stirred reactor. Coupling of the soot and chemistry solvers is shown to converge for both systems, however, numerical instabilities present significant challenges in the PSR case. Comparison with the experimental data for a PFR showed good agreement of the soot mass, and reasonable agreement of the particle size distribution. Two different soot particle models were used to simulate the PFR; a spherical particle model and a surface-volume model which takes some account of particle shape. The results for both models are compared. Additionally the stochastic soot solver is used to track the evolution of the C/H ratio of individual soot particles in the PFR for the first time.

Material from this preprint has been published in: Combustion and Flame 148 (3), 158-176, (2007)

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