著者

芝 定孝 平田 雄志 八木 俊策

出版者

Japan Society of Civil Engineers

雑誌

水工学論文集 (ISSN:09167374)

巻号頁・発行日

vol.43, pp.245-250, 1999-02-10 (Released:2010-08-25)

参考文献数

10

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Cloud droplet formation is an important process in water cycle between the earth and the atmosphere. In order to investigate the nonsteady growth of cloud droplets due to the condensation of the atmopheric water vapor on (NH4) 2 SO4 particles, a mathematical model has been constructed and the nonsteady growth has been simulated numerically with use of the mathematical model. The mathematical model is constituted by the conservation laws of water mass and heat energy and the state equation of ideal gas. As the speed of time variation of droplet heat QW is very fast compared with that of droplet mass mw, droplet temperature Ta can be treated as in steady state. The equilibrium droplet size ae is dependent on the 3/2 power of the initial radius aso of cloud condensation nucleus (NH4) 2SO4. The larger as0 is, the more the droplet grows in its equilibrium size ae. It takes much time for large condensation nucleus to attain the equilibrium size ae. It also has been cleared that Kelvin's equation is not always applicable to estimate the cloud droplet siz