Characterisation of soot particle size distribution through population balance approach and soot diagnostic techniques for a buoyant non-premixed flame

y Combustion-generated soot particles is a subject of great interest due to its existing and future use in research and industrial sectors. An in-house Direct Quadrature Method of Moments (DQMOM) based population balance model is constructed to investigate the evolution of soot particulate. Most numerical models assume the particle size to be monodispersed, while the proposed model enables the evaluation of real-time soot particle size distribution which further enhances prediction accuracies. The proposed model is fully coupled with all essential fire sub-modelling components and is specifically constructed for low-speed buoyant flames. Additionally, to better describe the combustion process of parental fuel, ethylene, the strained laminar flamelet model considering detailed chemical reaction mechanisms is adopted. Numerical simulation with the implementation of the proposed population balance soot model has been validated against an in-house co-flow burner experimental study and been compared with other numerical studies. The results demonstrated that the improved DQMOM soot model has significant improvement to the accuracy of simulation when compared to Moss-Brookes soot model. It was also discovered that by employing Moss nucleation law, modified NSC oxidation law and adopting fractal dimension value of 2.0, the DQMOM model produces the results with the best agreement against experimental data. (C) 2019 Energy Institute. Published by Elsevier Ltd. All rights reserved.