Damage on a solid-liquid interface induced by the dynamical behavior of injected gas bubbles in flowing mercury

Kogawa, Hiroyuki; Wakui, Takashi; Futakawa, Masatoshi

Fluids (Internet), 10(1), p.3_1 - 3_15, 2025/01

https://doi.org/10.3390/fluids10010003

Microbubbles have been applied in various fields. In mercury targets of spallation neutron sources, where cavitation damage is a crucial issue for the life estimation, microbubbles are injected into the mercury to absorb the thermal expansion of the mercury caused by the pulsed proton beam injection and reduce the macroscopic pressure waves, and result in reducing the damage. Recently, when the proton beam power was increased and the amount of injected gas bubbles was increased, unique damage morphologies were observed on solid-liquid interface. Detailed observation and numerical analyses revealed that the microscopic pressure emitted from the gas bubbles contracting is sufficient to form pit damage; i.e. the directions of streak-like defects which are formed by connecting pit damage coincides with the direction of gas bubble trajectories, and the distances between pits was understandable taking the natural period of gas bubble vibration into account. This indicates that the gas microbubbles to reduce the macroscopic pressure waves have potential to be inceptions of the cavitation damage due to the microscopic pressure emitted from gas bubbles. To completely mitigate the damage, we have to consider the two effects of injecting gas bubbles; reducing macroscopic pressure waves and microscopic pressure due to bubble dynamics.

Aseismic study of high temperature gas-cooled reactor core with block-type fuel(3rd report,effect of excitation directions and core support stiffness

;

Nihon Kikai Gakkai Rombunshu, C, 51(464), p.746 - 755, 1985/00

https://doi.org/10.1299/kikaic.51.746

no abstracts in English

Aseismic study of high temperature gas-cooled reactor core with block type fuel; 2nd report: An analytical method of two-dimensional vibration of interacting columns

Bull.JSME, 208(16), p.1610 - 1617, 1982/00

no abstracts in English

Seismic response of high temperature gas-cooled reactor core with block-type fuel,III; Vibration experiment of two-dimensional vertical slice core model

;

Journal of Nuclear Science and Technology, 18(7), p.514 - 524, 1981/00

https://doi.org/10.3327/jnst.18.514

no abstracts in English

One-Region Core ModelSeimic Test and Analysis for HTGR Core

;

JAERI-M 9199, 61 Pages, 1980/11

JAERI-M-9199.pdf:3.81MB

no abstracts in English