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

2020 Fiscal Year Final Research Report

• 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
• 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

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.

Free Research Field

流体工学

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．