에어로졸 입자의 이동, 성장, 소광을 모의하는 3차원 수치모델 개발 II: 흡습성장 및 소광 효과 모의

Abstract

The model reported in the companion paper was improved further and validated against field experiments. An interpolation subroutine was added to determine the flow field at any input wind speed and temperature conditions from the database prepared using the OpenFOAM simulations. The polydispersity of the aerosol emission is taken into account in the improved model. To account for the growth by condensation without moving the grown particles to larger sections, which causes numerical diffusion, additional variables representing the aerosol water content in each section were added. The coagulation subroutine was accordingly revised to take into account the particle size change due to condensation. The effects of particle hygroscopicity were added in the condensation subroutine. Hygroscopic growth was assumed to be completed instantly after emission because extensive simulations showed that hygroscopic growth reached 90 % of its destination within one time step in most cases. A method to determine the model parameter representing particle hygroscopicity experimentally is suggested. A set of simple field experiments was performed with three different levels of wind strength when wind speed and direction were maintained steady. The observed spatial distribution of aerosol plumes and resulting light extinction showed qualitatively good agreement with model predictions.