OR3-1
重力加速度が密閉容器内スロッシング現象に与える影響-ISS 軌道上実験で観測された液体挙動に関する数値解析Effect of gravity conditions on Sloshing Phenomena in
Sealed Vessel
草野素晴 1, 古市彦乃 1, 桜井誠人 2, 坂本佑介 2, 神吉誠志 2, 上野一郎 3Motoharu KUSANO1, Hikono FURUICH1, Masato Sakurai2, Yusuke SAKAMOTO2, Seiji
KAMIYOSHI2, Ichiro UENO3
1 東京理科大学大学院，Tokyo University of Science
2 宇宙航空研究開発機構，Japan Aerospace Exploration Agency
3 東京理科大学，Tokyo University of Science

Extensive and long-term manned lunar exploration is envisioned in the ARTEMIS program1). To achieve
this program, development of a manned pressurized rover equipped with a Regenerative Fuel Cell (RFC) isproceeding. For vehicles equipped with an RFC under reduced-gravity condition, it is essential to control thegenerated gas-liquid two-phase flow. One of the gas-liquid two-phase flow is the sloshing phenomena. Thesephenomena have been studied under normal and microgravity conditions2,3) as one of the importantphenomena in fluid engineering. On the other hand, there is a critical lack of knowledge on sloshingphenomena under reduced gravity. Therefore, in 2022, the Japan Aerospace Exploration Agency (JAXA)conducted a series of rotational swing experiments under reduced gravity on the International Space Station(ISS). Prior to this series of space experiments, we have conducted ground-based experiment and developed
a simulation model for prediction of the liquid motion with free surface 4). In this study, we will analyze thedata obtained from the space experiments in detail and investigate the effects of gravitational acceleration onsloshing phenomena. Furthermore, we will predict and reproduce the liquid behavior obtained from on-orbit
experiment using the simulation model.
Figure 1 shows the small rectangular vessel for (a) on–orbit experiment and (b) numerical simulation. The
sealed vessel is filled with liquid and gas. Figure 2 shows that the vessel is rotated side by side around its axisof rotation, which is parallel to the z axis through the centered point in the figure. The maximum angle ofrotation 𝜃max was fixed at 10 degrees. The direction of gravity was set to be in the negative direction of the yaxis. Gravitational acceleration was varied under three conditions: normal (on the ground) (G), on the Moon(G/6), and on the Mars (G/3). The vessel was rotated while varying the oscillation frequency, and the motionof the liquid with the free surface were observed. The interFoam solver of OpenFOAM (ver. 9) is used as thenumerical simulation solver, which solves gas-liquid two-phase flows using the Volume of Fluid (VOF)
method. A moving mesh function is applied to reproduce the reciprocating rotational motion of the vessel
around its axis.
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Figure 3 shows (a) the first peak amplitude reached for each normalized gravity and (b) the normalized
frequency at that time. These findings indicate that in the sloshing phenomena, the amplitude peak and thevalue of the frequency at which the peak is reached are shifted. In this presentation, we will discuss the gravity
dependence on sloshing phenomena through on-orbit experiment and numerical simulation.

Figure 1. Rectangular vessels for sloshing test

Figure 2. Coordinate systems of(a) on-orbit experiment and (b) numerical model.

target geometry.

Figure 3. Gravity dependences of (a) normalized first peak liquid-level amplitude of free surface 𝐴𝑚𝑎𝑥 /𝐿and (b) normalized frequency at maximum amplitude of free surface 𝑓𝐴𝑚𝑎𝑥 /𝑓1 .

References
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2)

3)
4)

NASA: Artemis Plan – NASA`s Lunar Exploration Program Overview, 2020, NP-2020-05-2853-HQ,
URL: https://www.nasa.gov/wp-content/uploads/2020/12/artemis_plan-20200921.pdf?emrc=f43185, (visited on the7th August 2024)
J.H. Yung, H. S. Yoon and C. Y. Lee: Effect of natural frequency models on sloshing phenomenon in a rectangulartank. International Journal of Naval Architecture and Ocean Engineering, Journal of Aeronautics, 7(3) (2015), 580-594.
DOI: https://doi.org/10.1515/ijnaoe-2015-0041
S. Kaneko, T. Ishiyama and T. Sawada: Journal of Physics: Conference Series, 412(2013), 012018,
DOI: 10.1088/1742-6596/412/012018
S. Chino, G. Murakami, M. Kusano, K. Kurose, Y. Sakamoto, K. Kazuya, M. Sakamoto, M. Sakurai and I. Ueno:
International Journal of Microgravity Science and Application, 40(2) (2023), 400202,
DOI: https://doi.org/10.15011/jasma.40.400202© 2024 by the authors. Submitted for possible open access publication under
the terms and conditions of the Creative Commons Attribution (CC BY) license(http://creativecommons.org/li censes/by/4.0/).

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