2019 Fiscal Year Final Research Report
Anisotropic turbulent clustering mechanism of gravitational-settling spherical and nonspherical inertial particles
| Project/Area Number |
17K14598
|
|---|
| Research Category |
Grant-in-Aid for Young Scientists (B)
|
| Allocation Type | Multi-year Fund |
|---|
| Research Field |
Fluid engineering
|
|---|
| Research Institution | Japan Agency for Marine-Earth Science and Technology |
|---|
Principal Investigator |
Matsuda Keigo 国立研究開発法人海洋研究開発機構, 付加価値情報創生部門(地球情報基盤センター), 研究員 (50633880)
|
|---|
| Project Period (FY) |
2017-04-01 – 2020-03-31
|
| Keywords | 乱流 / 混相流 / 雲 / 直接数値シミュレーション / レーダー観測 |
|---|
| Outline of Final Research Achievements |
Effects of nonuniform cloud particle distribution in turbulence (turbulent clustering) on increase of the radar reflectivity in cloud observations were investigated using a direct numerical simulation of particle-laden turbulence. A model to predict the increase of radar reflectivity was developed considering the influence of gravitational settling and polydisperse particle sizes, and the effects of turbulent clustering in radar observations of realistic convective clouds were presented quantitatively. In addition, the effects of turbulent clustering of ice particles (non-spherical particles) were clarified.
|
| Free Research Field |
熱流体工学
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究により，雲粒子の乱流クラスタリングによるレーダー反射因子の増加量を定量的に推定することが可能となった．本研究で構築したモデル式を応用することでレーダー観測によって対流雲中の乱流状態を推定できる可能性がある．対流雲中の乱流は衝突併合による雲粒の成長を促進させることから，レーダー観測によって対流雲中の乱流状態を推定することにより，突発的豪雨の早期検知に役立つ可能性が期待される．
|
