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ISS 軌道実験で得られた密閉容器内スロッシング現象での周波数応答に関する検証
Verification of on-orbit experiments aboard the ISS onfrequency response in sloshing phenomenon
伴優希 1, 古市彦乃 2, 草野素晴 2, 桜井誠⼈ 3, 坂本佑介 3, 神吉誠志 3, 上野⼀郎 1
Yuki BAN1, Hikono FURUICHI2, Motoharu KUSANO2, Masato SAKURAI3, Yusuke SAKAMOTO3,Seiji KAMIYOSHI3, and Ichiro UENO1
東京理科⼤学，Tokyo University of Science
東京理科⼤学⼤学院，Tokyo University of Science
3 宇宙航空研究開発機構，Japan Aerospace Exploration Agency
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For future space explorations such as the ARTEMIS program1) and the "Moon to Mars" program2), theelucidation of gas-liquid two-phase flow is essential and indispensable. The lunar rover being developed forlunar surface operations and the Space Launch System (SLS) rocket, for instance, are equipped with liquidtanks: Extreme liquid motion in the tanks must be controlled because it would lead to vigorous momentum
variation as well as leakage of liquid from the tanks, resulting in horrible accidents that must be avoided. TheJapan Aerospace Exploration Agency (JAXA) conducted a series of experiments on behaviors of liquid
partially filled in different types of closed vessels on the International Space Station (ISS) in 2022. One of theseexperiments is on the sloshing phenomenon within a small rectangular container3) (Fig. 1 (a) and (b)). In theon-ground experiments with the Engineering Model3) as well as the on-orbit experiments, a peculiar frequency
response of the liquid was identified (Fig. 1 (c)). This study focuses on the response of liquid partially filled ina rectangular closed vessel in swinging motion.
Target geometry of the present study is rectangular vessel: Figure 1 illustrates the front views of small

Figure 1. Small rectangular container used in (a) ground experiment and (b) numerical simulation, andfrequency responses of liquid motion under initial liquid level h0 = 9.33 mm by (c) on-ground experiments3)
with water (as denoted as (w)) and n-Hexane (as denoted as (h)) and by (d) present numerical simulation byapplying triangle wave with n-Hexane.
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rectangular container used in (a) the on-ground experiments and (b) the numerical simulations. The container
is reciprocally swung around a rotating axis (as shown in the circle) normal to the front and rear panels. In theexperiments, the vessel is oscillated by the stepping motor. The oscillation is realized by varying the angle via
triangle wave with the designated period corresponding the inverse of excitation frequency. The motion ofgas-liquid interface is observed with a digital camera from the front of the vessel. The detail of apparatus isintroduced in Ref3). The test liquid and gas in the vessel are n-Hexane and the air, respectively. In the numericalsimulation, the behaviors of test fluids are reproduced by the equations of continuity and Navier-Stokes
equation by applying the Continuum Surface Force (CSF) method. These governing equations are solved by
the InterFoam solver of OpenFOAM (ver. 9).
To elucidate peculiar frequency response of induced motion (e.g., at f/f1,e ~ 1.4 in Fig. 1 (c)), a series ofnumerical simulation with oscillating the vessel by applying not only the sinusoidal function3) but also thetriangle function. Figure 1 (d) shows a typical example of the correlation between the amplitude of gas-liquidinterface oscillation and excitation frequency with the initial liquid level h0 = 9.33 mm by applying the triangle
wave. The on-ground experimental results are also plotted. The excitation frequency of triangle function isdefined as the inverse of fundamental period 𝜏(tri), f(tri): =1/ 𝜏(tri). Slight bump of the amplitude is successfully
reproduced at around f/f1 ~ 1.43 (or f(tri) = 6.33 Hz) by numerical simulation. In the poster presentation, we will
discuss the effect of temporal variation of swinging angle on sloshing phenomenon.
References
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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, (accessed on 8August, 2024)
NASA: Moon to Mars Objects, 2022, URL: https://www.nasa.gov/wp-content/uploads/2022/09/m2m-objectives-execsummary.pdf?emrc=119caf , (accessed on 8 August, 2024)
S. Chino, G. Murakami, M. Kusano, K. Kurose, Y. Sakamoto, K. Ssuzuki, M. Sakurai and I. Ueno: Behaviors ofLiquid Partially Filled in Sealed Vessels under Normal Gravity Conditions – Toward On-orbit Experiment abroad
the ISS –, Int. J. Microgravity Sci. Appl. 40(2) (2023), 400202. DOI: 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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