Study on the formation mechanism of the size-distribution spectrum of atmospheric aerosol particles using the statistical theory of turbulence

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K13611
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 17020:Atmospheric and hydrospheric sciences-related
• Research Institution: Nagoya Institute of Technology
• Principal Investigator: Saito Izumi 名古屋工業大学, 工学(系)研究科(研究院), 助教 (70798602)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 乱流理論 / 衝突 / エアロゾル粒子 / 乱流変調

Outline of Final Research Achievements

We investigated the mechanism for the formation of the size-distribution spectrum of atmospheric aerosol particles using the statistical theory of turbulence and direct numerical simulations. We showed theoretically that the size-distribution spectrum due to collision/coalescence of particles in turbulence shows the slope of -2 and confirmed the prediction by direct numerical simulations. We also found that turbulence modulation by small particles due to drag force is characterized by a novel parameter referred to as the flow relaxation time.

Free Research Field

流体工学、大気科学

Academic Significance and Societal Importance of the Research Achievements

大気中に存在する微小なエアロゾル粒子は、大気の放射特性や降雨との関係を通じて気象・気候に重要な影響を与える。本研究は、乱流統計理論と大規模数値シミュレーションにより、これら微小粒子の乱流中における衝突・合体によって、粒径分布スペクトルが形成されるメカニズムを明らかにした。この成果は、今後の気象予報のためのモデル開発や精度向上に貢献することが期待される。