Theoretical elucidation for spatiotemporal structures of turbulent particle transports and landform patterns in solid-gas multiphase flow

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K14353
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: Niigata University
• Principal Investigator: Niiya Hirofumi 新潟大学, 研究推進機構, 特任助教 (80794982)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 固気混相流 / 飛砂 / 飛雪 / 数値モデリング / Large-eddy simulation / スプラッシュ過程

Outline of Final Research Achievements

This study aimed to investigate the mechanism of blown sand and drifting snow with complex spatio-temporal structures. I developed a new model for turbulent transports of solid particles named as "Large-eddy simulation coupled with Lagrangian snow transport model." Numerical simulations showed the following result. The intermittent transport is formed in the low-wind condition because of the stop-start saltation movement, whereas the continuous transport exhibiting the streak pattern in the streamwise direction is formed in the relatively high-wind condition.

Free Research Field

非線形動力学

Academic Significance and Societal Importance of the Research Achievements

本研究成果である固体粒子の乱流輸送モデルは，粒子運動力学と流体力学で培われた手法を相互に組み合わせており，既存の観測・実験的表式を理論的に裏付けするとともに，これまで計測が困難であった地表面近傍の輸送特性や跳躍・浮遊層に及ぶ輸送構造の変動性を解明する新たな手法となり得る．また，本成果は，砂嵐や吹雪など固気混相流の自然現象の高精度予測，例えば，発生条件やその強度の推定に繋がり，自然災害の防災・減災に資することが期待される．