Study on mechanism of the cavitation erosion mitigation in narrow gap under flowing condition

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K03888
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Japan Atomic Energy Agency
• Principal Investigator: Takashi Naoe 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 J－PARCセンター, 研究副主幹 (00469826)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: キャビテーション / 圧力波 / 高速度撮影 / 水中火花放電 / 壊食損傷

Outline of Final Research Achievements

The purpose of this study is to elucidate the mechanism of cavitation erosion in the narrow gap between the parallel wall under the flowing condition, and its proton beam power dependency for the liquid mercury target vessel of the pulsed spallation neutron source.
Growing and collapsing behavior of cavitation bubble generated by an electric spark discharge in water was observed using high-speed video camera, and their collapsing pressure was measured as vibration of wall aiming to investigate the effect of gap width and flow velocity on damage formation.

Free Research Field

機械工学

Academic Significance and Societal Importance of the Research Achievements

液体金属を標的に用いたパルス核破砕中性子源は，日本の他，米国でも開発が進められており，同様に標的容器のキャビテーションによる壊食損傷が標的の高出力化及び長寿命化を妨げる因子になっている．米国では，先行して狭隘壁構造の標的容器を採用している．狭隘部のキャビテーションによる損傷は，標的容器の寿命に直結するため，中性子源開発に係る国際ワークショップでも注目度は高く，狭隘部におけるキャビテーション損傷の解明と出力依存性に関する評価は，世界的に進められている中性子源開発に大きく寄与する．