Inverse Gaussian distributed method of moments for agglomerate coagulation due to Brownian motion in the entire size regime

The objective of this paper is to derive a model for studying the collision-coalescence dynamics of agglomerates. Accordingly, we first extend the inverse Gaussian distributed method of moments (IGDMOM; J. Atmospheric Sci., 2020, 77(9), 3011-3031) to solve the Smoluchowski coagulation equation for fractal-like agglomerates undergoing Brownian coagulation in the entire size regime. The extended IGDMOM, denoted as E-IGDMOM, is integrated with two solutions, namely Dahneke's solution and the harmonic mean solution, for deriving moment ordinary differential equations (MODEs) for Brownian coagulation in the free molecular regime and in the continuum-slip regime. Comparative analyses demonstrate that the E-IGDMOM achieves nearly the same efficiency as that of the Taylor-series expansion MOM (TEMOM) and the lognormal MOM (log MOM); nevertheless, it has higher precision than that of the log MOM in the free molecular regime and nearly the same precision as that of the TEMOM and log MOM in the transient regime. Regarding the skewness and kurtosis of size distribution functions, compared with the log MOM and IGDMOM, we observe that the E-IGDMOM yields values that are much closer to those of the quadrature MOM. (C) 2021 Elsevier Ltd. All rights reserved.