Flow Dynamics in Liquid-metal Two-phase Flow
Purpose
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Liquid metal two-phase flows are an essential feature in continuous casting process.
For instance, Argon gas are injected in ladles for homogenization of the melt and removing the undesired inclusions by transporting them towards the slag layer at the free surface.
Furthermore, Argon gas is added to the steel flow to avoid clogging. Therefore, it is important estimate the bubbles behavior.
Liquid-metal two-phase flow has larger liquid-to-gas density ration and higher surface tension than air-water two-phase flow.
Hence, it is required to evaluate an applicability of existing models on liquid-metal through the experimental researches. However, the experimental data is so limited because of the difficulty of the flow measurements.
Aim of this study is clarification of flow dynamics in liquid-metal two-phase flow. Ultrasonic tomography developed in this laboratory and radiography were applied for measuring void distribution in liquid-metal two-phase flow.
Research content
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The eutectic GaInSn alloy is used as a working fluid. The GaInSn is liquid phase at room temperature. The GaInSn was pooled in a cylindrical container, and Argon gas was injected through a nozzle at a bottom of the container.
The instantaneous void distribution was evaluated using a ultrasonic tomography developed in this laboratory.
Figures show the pseudo three-dimensional void distribution in water-Argon and GaInSn-Aron bubble columns. The vertical axis represents time, and these are the results less than 1 sec.
The temporal resolution that obtaining a cross-sectional image was set at 1 ms, and the void distributions were continuously obtained at 500 frames/sec.
As the surface tension of the liquid-metal is larger than that of water, bubbles shape becomes more spherical than that in water. As a result, bubbles deformation and the oscillating movement became small in liquid-metal two-phase flow.
Publications
H. Murakawa, S. Maeda, S. Eckert
Effects of a horizontal magnetic field on the cross-sectional distribution of gas bubbles chain rising in a gallium alloy, International Journal of Multiphase Flow 170, 104649 (2024).
https://doi.org/10.1016/j.ijmultiphaseflow.2023.104649