Development of submicron hot-wire sensor for experiments of high Reynolds number turbulence

• Project/Area Number: 17K18939
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Aerospace engineering, Naval and maritime engineering, and related fields
• Research Institution: Tokyo Metropolitan University
• Principal Investigator: ASAI Masahito 首都大学東京, システムデザイン研究科, 客員教授 (00117988)
• Co-Investigator(Kenkyū-buntansha): 高木 正平 首都大学東京, システムデザイン研究科, 客員教授 (10358658) ; 稲澤 歩 首都大学東京, システムデザイン研究科, 准教授 (70404936) ; 金子 新 首都大学東京, システムデザイン研究科, 准教授 (30347273)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000); Fiscal Year 2019: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2017: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 流体工学 / 熱線風速計 / 乱流計測 / 熱線風速計センサ / 熱線センサ / 壁乱流 / 高レイノルズ数 / 航空宇宙工学

Outline of Final Research Achievements

Submicron hot-wire sensor (125 nm thick, 0.1 mm long) which is responsible for experiments on high-Reynolds-number turbulence was produced using a transfer-printing technique. The sensor response to velocity fluctuations was tested using a newly-developed low-noise constant-temperature hot-wire anemometer (CTA) to verify its performance. In addition, we reconsidered the criterion on the sensor aspect ratio (l/d) for accurately measuring velocity fluctuations, based on careful experiments using specially-designed hot-wire probes, and concluded that the criterion (l/d not less than 200) could be mitigated significantly.

Academic Significance and Societal Importance of the Research Achievements

乱流構造に関する信頼できる実験データを得るためにはセンサの時間・空間分解能を保証することが重要であり，サブミクロン薄膜型熱式センサの製作技術は特に高レイノルズ数域の乱流実験の研究者の要望するものであり，本研究はそれに応えるものである．同時に開発した低ノイズかつ高周波数応答のコンパクト熱線風速計システムは乱流だけでなく流体実験に広範囲に利用できる高性能の熱線風速計システムである．また，長年にわたり推奨されてきたセンサアスペクト比（センサ径／長さ）200以上という制約条件を半分程度にまで緩和できることを綿密な実験により示したことは実験流体力学に対する大きな貢献と言える．

Research Products

• [Journal Article] Improvement of signal-to-noise ratio of the constant-temperature hot-wire anemometer using transfer function (2020)
  • Author(s): Ayumu Inasawa, Shohei Takagi, Masahito Asai
  • Journal Title: Measurement Science and Technology Volume: 31 Issue: 5 Pages: 055302-055302
  • DOI: 10.1088/1361-6501/ab6916
  • Peer Reviewed
• [Presentation] A simple method for determination of the frequency response of the constant-temperature hot-wire anemometer (2019)
  • Author(s): Shohei Takagi, Ayumu Inasawa, Masahito Asai
  • Organizer: 5th International Conference on Sensors and Electronic Instrumentation Advances (SEIA)
  • Int'l Joint Research
• [Presentation] 定温度型熱線風速計の広帯域周波数応答特性を求める簡易手法 (2019)
  • Author(s): 高木正平，稲澤歩，淺井雅人
  • Organizer: 日本流体力学会年会2019
• [Presentation] 熱線のセンサ長と直径の比が周波数応答特性に及ぼす影響に関する実験的研究 (2019)
  • Author(s): 稲澤歩，高木正平，淺井雅人
  • Organizer: 日本流体力学会年会2019
• [Presentation] 乱流計測に求められる熱線センサのアスペクト比と空間分解能 (2018)
  • Author(s): 髙木正平，川田大典，稲澤歩，淺井雅人
  • Organizer: 日本流体力学会2018
• [Patent(Industrial Property Rights)] 熱式流速計 (2019)
  • Inventor(s): 髙木正平，淺井雅人，稲澤歩
  • Industrial Property Rights Holder: 髙木正平，淺井雅人，稲澤歩
  • Industrial Property Rights Type: 特許
  • Industrial Property Number: 2019-205548
  • Filing Date: 2019