Development of Innovative Numerical Model of Cavitation through Liberation Experiment in Oil and Simulation of Tuebulence

• Project/Area Number: 18K18819
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 19:Fluid engineering, thermal engineering, and related fields
• Research Institution: Tohoku University
• Principal Investigator: Iga Yuka 東北大学, 流体科学研究所, 教授 (50375119)
• Project Period (FY): 2018-06-29 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000); Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2018: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000)
• Keywords: 気体性キャビテーション / 溶存気体 / 析出 / テイラー渦 / 油圧作動油 / キャビテーション / 乱流 / 溶存空気 / 数値解析

Outline of Final Research Achievements

In this study, decompression experiment of concentric rotating two cylinders with oil between the narrow clearance was done in order to clarify the characteristics of occurrence of gaseous cavitation in a shear flow field. As the result, it was shown that the gaseous cavitation is easy to occur in the flow filed with higher shear and lower pressure-drop. And it was newly found that the occurrence characteristics are classified into two regions; one is non-equilibrium separation where the occurrence pressure decreases according to increase the decompression speed and the other is equilibrium separation where the occurrence pressure is constant despite of the change of the decompression speed. Furthermore, the equation of the boundary decompression speed between the two characteristics and the non-equilibrium occurrence pressure were derived.

Academic Significance and Societal Importance of the Research Achievements

本研究で得られた気体性キャビテーションの発生条件をキャビテーション数値解析モデルに適用することにより，より現実に近いキャビテーション発生の数値予測が可能となる．キャビテーションの発生予測ができれば，キャビテーションによって性能が低下してしまうポンプの高性能設計が可能となる．特に，ロケットエンジン以外では未だ開発されておらず，しかし，今後来たる水素社会において必須となりこれから開発が始まる水素輸送ポンプにおいて，その吸込性能を向上する最適設計が可能となり，水素サプライチェーンのコスト低減に貢献できると期待できる．

Research Products

• [Journal Article] 非定常キャビテーション流れの流動刺激が促進する溶存気体の析出に関する一考察 (2019)
  • Author(s): 伊賀由佳, 槙井大輝, 佐々木裕章
  • Journal Title: 日本機械学会論文集 Volume: 85 Pages: 19-00217
  • NAID: 130007733875
  • Peer Reviewed
• [Presentation] An Experimental Consideration of Occurrence Condition of Gaseous Cavitation in Oil (2021)
  • Author(s): Yuka Iga, Junnosuke Okajima, Shunpei Takahashi, and Yousuke Ibata
  • Organizer: 11th International Symposium on Cavitation
  • Int'l Joint Research
• [Presentation] In-Situ Measurement of Liberation of a Dissolved Gas in Unsteady Cavitating Flow in a Water (2019)
  • Author(s): Daiki Makii, Hirotoshi Sasaki, Yuka Iga
  • Organizer: ASME-JSME-KSME Joint Fluids Engineering Conference 2019
  • Int'l Joint Research
• [Presentation] Numerical Study of Appearance of Gaseous Cavitation around a Stator Blade in Torque Converter (2019)
  • Author(s): Shumpei Takahashi, Tomohiko Usui, Yuka Iga
  • Organizer: 15th Asian International Conference on Fluid Machinery
• [Presentation] Development of gaseous cavitation model in hydraulic oil flow considering the effect of dynamic stimulation (2018)
  • Author(s): Yosuke IBATA, Yudai MATSUURA, Shunpei TAKAHASHI, Yuka IGA
  • Organizer: 29th IAHR Symposium on Hydraulic Machinery and Systems
• [Presentation] 作動油中での気体性キャビテーション発生における流動刺激の影響 (2018)
  • Author(s): 井畑陽輔，薄井友彦，伊賀由佳
  • Organizer: 日本流体力学会年会2018