A new weighted fraction Monte Carlo method for particle coagulation
International Journal of Numerical Methods for Heat & Fluid Flow
ISSN: 0961-5539
Article publication date: 4 February 2021
Issue publication date: 26 August 2021
Abstract
Purpose
The purpose of this study is to investigate the aerosol dynamics of the particle coagulation process using a newly developed weighted fraction Monte Carlo (WFMC) method.
Design/methodology/approach
The weighted numerical particles are adopted in a similar manner to the multi-Monte Carlo (MMC) method, with the addition of a new fraction function (α). Probabilistic removal is also introduced to maintain a constant number scheme.
Findings
Three typical cases with constant kernel, free-molecular coagulation kernel and different initial distributions for particle coagulation are simulated and validated. The results show an excellent agreement between the Monte Carlo (MC) method and the corresponding analytical solutions or sectional method results. Further numerical results show that the critical stochastic error in the newly proposed WFMC method is significantly reduced when compared with the traditional MMC method for higher-order moments with only a slight increase in computational cost. The particle size distribution is also found to extend for the larger size regime with the WFMC method, which is traditionally insufficient in the classical direct simulation MC and MMC methods. The effects of different fraction functions on the weight function are also investigated.
Originality Value
Stochastic error is inevitable in MC simulations of aerosol dynamics. To minimize this critical stochastic error, many algorithms, such as MMC method, have been proposed. However, the weight of the numerical particles is not adjustable. This newly developed algorithm with an adjustable weight of the numerical particles can provide improved stochastic error reduction.
Keywords
Acknowledgements
This work was supported by the research studentship grant, the General Research Fund, Research Grants Council of the Hong Kong Special Administrative Region, China (Project No. PolyU 152663/16E), and the Central Research Grant (Project No. B-Q54U) and Department of Mechanical Engineering of The Hong Kong Polytechnic University.
Citation
Jiang, X. and Chan, T.L. (2021), "A new weighted fraction Monte Carlo method for particle coagulation", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 31 No. 9, pp. 3009-3029. https://doi.org/10.1108/HFF-07-2020-0449
Publisher
:Emerald Publishing Limited
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