Explicit method for unsteady fluid dynamics simulation

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18770
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 23:Architecture, building engineering, and related fields
• Research Institution: Kyushu University
• Principal Investigator: Ikegaya Naoki 九州大学, 総合理工学研究院, 准教授 (70628213)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: 陽的解法

Outline of Final Research Achievements

The velocity fields around buildings are solved using computational fluid dynamics approaches; however, unsteady simulations require huge numerical demands. Therefore, this research proposed a new calculation approach explicated determine the velocity field based on Eulerian governing equations. First, a new concept to consider the virtual particles is introduced to theoretically determine the propagation velocity of the sound wave and pressure values based on the numerical grid system. Second, the velocity fields were simulated using the proposed method and conventional method relaying on implicit numerical approaches. The results clearly showed that proposed method can accurately reproduce the velocity field with shorter numerical simulation time. The study, therefore, was able to achieve the research aims targeted to propose a new methodology which theoretically reasonable to determine the pressure fields with less computational costs.

Free Research Field

建築環境工学

Academic Significance and Societal Importance of the Research Achievements

計算負荷軽減法には，代数計算効率や計算機性能の向上などの計算機科学的な方法が執られてきたが，本研究課題の遂行により，解析アルゴリズムを抜本的に改善することができた．これにより，長年適用されてきた非圧縮性流体の解析アルゴリズムを見直し，定常計算から非定常計算への転換のボトルネックを解決する足がかりを提供することができ，陽的解法の実用化に向けた大きなブレークスルーをもたらすことができたと考えられる．また，提案手法の数値流体力学的な解釈だけではなく，明確な理論展開を行ったことにより，当該分野だけではなく，流体力学の発展に貢献できる成果を残した．