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Measurement of Aerodynamic Forces near Critical Reynolds Number Acting on a Rotating Sphere

Research Project

Project/Area Number 18K17851
Research Category

Grant-in-Aid for Early-Career Scientists

Allocation TypeMulti-year Fund
Review Section Basic Section 59020:Sports sciences-related
Research InstitutionTohoku University

Principal Investigator

Okuizumi Hiroyuki  東北大学, 流体科学研究所, 技術専門職員 (60647957)

Project Period (FY) 2018-04-01 – 2022-03-31
Project Status Completed (Fiscal Year 2021)
Budget Amount *help
¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
Fiscal Year 2020: ¥390,000 (Direct Cost: ¥300,000、Indirect Cost: ¥90,000)
Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2018: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Keywords回転球 / マグナス効果 / 負のマグナス効果 / 支持干渉 / 磁力支持天秤装置 / 磁気力浮揚 / 空間的平均化 / 球 / 抵抗 / 回転
Outline of Final Research Achievements

The objective was to clarify the aerodynamic characteristics of a rotating sphere with dimples on the surface using the 1-m magnetic suspension and balance system (1-m MSBS) at the Institute of Fluid Science, Tohoku University.
A magnetic suspension and balance system is an effective way to avoid support interference in wind tunnel testing.
I made it possible with magnetic levitation of the rotating sphere by improving the position sensor system. And I adopted air-jet nozzles to rotate the sphere model suspended magnetically. Applying this method, a wind tunnel test was conducted at the wind speed of 7m/s (Reynolds number = 6.5 × 10^4) and rotational speed within 600 rpm. An occurrence of the drag crisis was confirmed, and drastically decreasing the Magnus force was also measured.

Academic Significance and Societal Importance of the Research Achievements

磁力支持天秤装置による回転球の空力試験技術を開発したことで、今までほとんど例のなかった、支持干渉のない真の回転球の空力特性を調査する環境が整った。最初の風洞試験では、回転する球模型に働く空気抵抗やマグナス力が、その回転数の変化に伴って劇的に変化する様子を捉えた。今後この技術を用いることで、回転球の空力現象解明や、スポーツ分野でよく目にするディンプル状やシーム状の表面性状をもつ球状物体の回転時の空力特性解明が期待される。また、本技術を発展させ、球から形状が大きく異なる強風災害の飛散物形状である角柱などにも応用を広げることで近年増加する強風被害対策にも貢献できる。

Report

(5 results)
  • 2021 Annual Research Report   Final Research Report ( PDF )
  • 2020 Research-status Report
  • 2019 Research-status Report
  • 2018 Research-status Report
  • Research Products

    (3 results)

All 2022 2021

All Presentation (3 results) (of which Int'l Joint Research: 2 results)

  • [Presentation] Wind Tunnel Test Method Using a 1-m Magnetic Suspension and Balance System for Measuring Aerodynamic Force Acting on Rotating Sphere2022

    • Author(s)
      Hiroyuki Okuizumi, Hideo Sawada, Yasufumi Konishi, Shigeru Obayashi, Keisuke Asai
    • Organizer
      The 7th International Conference on Jets, Wakes and Separated Flows 2022
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Position Sensing Method for Rotating Sphere in 1-m Magnetic Suspension and Balance System2021

    • Author(s)
      Hiroyuki Okuizumi, Hideo Sawada, Yasufumi Konishi, Shigeru Obayashi, Keisuke Asai
    • Organizer
      Eighteenth International Conference on Flow Dynamics
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 1-m 磁力支持天秤装置を用いた回転する球の風洞実験法の開発2021

    • Author(s)
      奥泉 寛之, 澤田 秀夫, 小西 康郁, 大林 茂, 浅井 圭介
    • Organizer
      日本機械学会 シンポジウム:スポーツ工学・ヒューマンダイナミクス2021
    • Related Report
      2021 Annual Research Report

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Published: 2018-04-23   Modified: 2023-01-30  

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