Toward improved accuracy of macroscopic modeling of hydrodynamic forces based on undisturbed flow

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K04703
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 22040:Hydroengineering-related
• Research Institution: Shizuoka University
• Principal Investigator: Yokojima Satoshi 静岡大学, 工学部, 准教授 (80432194)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: キャノピー流れ / 抗力モデル / undisturbed flow / 計算流体力学

Outline of Final Research Achievements

A drag-force model is essential in practical predictions of flows around vegetation/urban canopies. However, the macroscopic model has a clear bottleneck: how one can obtain a proper distribution of drag coefficient for practical applications. Here particular attention is paid to undisturbed flow as a representative velocity scale required in the empirical formulation relating the drag force to an obstacle with the flow around it. The present study clearly has shown that (i) employing the undisturbed flow as the representative velocity can improve the prediction accuracy, and (ii) the prediction accuracy of the drag-force model becomes deteriorated in nonequilibrium flows. Since direct evaluation of the undisturbed flow is impractical in general, it is important to establish an efficient method for estimating the undisturbed flow from the corresponding disturbed flow field.

Free Research Field

環境流体力学

Academic Significance and Societal Importance of the Research Achievements

何等かの障害物を過ぎる流れの高精度かつ高効率な予測に対する需要は非常に大きく、抗力係数を利用したアプローチはその有力手法であるものの、任意の障害物群に対して適切な抗力係数を設定できる一般的方法は未だ得られていない。本研究はその鍵となる代表速度に関して検討したもので、undisturbed flowの有用性を示した。本研究結果は関連研究に大きなインパクトを有し、今後のundisturbed flowの活用や効率的推定に関する新たな研究の活性化が期待できる。