에어로졸 입자의 이동, 성장, 소광을 모의하는 3차원 수치모델 개발 I: 모델 구조와 예비 실험

Abstract

An integrated aerosol model that traces the changes in the temporal, spatial, and size distribution of the aerosol particles as well as their light extinction effects was developed. An open-source software OpenFOAM was used to predict the change in flow field due to heat emission by combustion. The flow field was shown to be closely dependent on the strength of heat emission and initial wind field. Advection, diffusion, gravitational settling, thermophoresis, coagulation, and condensation are taken into account in the model. Coagulation is solved separately from other aerosol mechanisms to reduce the computation time due to highly non-linear coagulation term. A semi-implicit scheme was used to solve the coagulation equation using a larger time step than that for the other mechanisms. The calculations of the growth due to coagulation and condensation were validated by comparing with analytical solutions. This paper explains the model structure and theories used for the component submodules and presents preliminary test results in the case of a typical combustion aerosol. Further modification and improvement of the model and its application to the prediction of light extinction effect in the atmosphere will be given in the companion paper.