A direct expansion method of moments for Brownian coagulation

Abstract

We propose a new method of moments for solving a coagulation equation based on the Taylor-expansion method of moments (TEMOM). In this model, the closure of the moment equations is achieved by using the Taylor expansion technique, and the fractional-order moments can be used to improve the accuracy of the results. The newly proposed method has no prior requirement for the shape of the particle size distribution. By comparing it with other known methods both in free molecular and continuum regimes, the new approach is found to be the most accurate method. The results show that the predictions of the lower-order moments are not significantly influenced by the higher-order ones, and the higher-order moments are not necessary if one intends to increase the accuracy of the numerical predictions.