Accelerating the Lagrangian Method for Modeling Transient Particle Transport in Indoor Environments

摘要

Computational fluid dynamics (CFD) with the Lagrangian method has been widely used in predicting transient particle transport in indoor environments. A large number of particles are needed in the Lagrangian tracking in order to obtain statistically meaningful results. Traditionally, modelers have conducted an independence test in order to find a reasonable value for this particle number. However, the unguided process of an independence test can be highly time-consuming. Therefore, this investigation developed a method for estimating the necessary particle number in the Lagrangian method. The results show that the estimation method can provide the necessary particle number with a reasonable magnitude. This study further proposed the superimposition and time-averaging methods to reduce the necessary particle number. When compared with experimental data, predictions of transient particle transport in indoor environments by the combined Lagrangian, superimposition, and time-averaging method with the estimated particle number are reasonably accurate.