2019 Fiscal Year Final Research Report
Drag force and flow field measurement of a sphere in the low Reynolds number and high Mach number flows using magnetic suspension and balance system
| Project/Area Number |
18K18818
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 19:Fluid engineering, thermal engineering, and related fields
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| Research Institution | Tohoku University |
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Principal Investigator |
Nonomura Taku 東北大学, 工学研究科, 准教授 (60547967)
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| Co-Investigator(Kenkyū-buntansha) |
半田 太郎 豊田工業大学, 工学(系)研究科(研究院), 教授 (30284566)
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| Project Period (FY) |
2018-06-29 – 2020-03-31
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| Keywords | 流体力学 / 低レイノルズ数 / 超音速 / 遷音速 / 高マッハ数 / 固気混相流 / 磁力支持 |
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| Outline of Final Research Achievements |
In this research project, a magnetic support device which enables noncontact visualization experiments of flow around (a) sphere(s) under low Reynolds number and high Mach number conditions was constructed, and the flow field and the drag coefficient around a single and multiple sphere(s) were clarified. An experimental device which releases a sphere supported by a magnetic force near the wall when the flow is generated was constructed. The flow fields around the sphere and the drag coefficients were clarified with this device. Detailed characteristics of the flow field such as the vortex structure generated around a single sphere were clarified. The obtained drag coefficient was higher than those of the previous models. In addition, the flow field and aerodynamic force of multiple spheres were clarified, and the aerodynamic forces were clarified to act in the direction in which the spheres separate in the range we investigated in this research.
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| Free Research Field |
航空宇宙流体力学
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| Academic Significance and Societal Importance of the Research Achievements |
低レイノルズ数・高マッハ数条件の球周り流れは，ロケット打ち上げ時の噴流の中に含まれるアルミナ粒子，噴流からの音響波低減のために撒かれる水滴，高速での固体粒子燃焼などに見られる．このような条件での高速固気混相乱流に関して，粒子がどのように振る舞うかということはこれまで全く明らかでは無かったため，このような条件において実験観察を行うことで，その特徴を明らかにしたことは学術的に非常に価値が高い．また，本研究成果に基づきロケット打ち上げ時や高速燃焼時などの乱流場の解明・モデル化を行うことで，今後の輸送機器・燃焼機器の高性能化につながると考えられる．
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