This article is a follow-up report of the status of the electrostatic levitation furnace research activities onboard the International Space Station (ISS). Capability of drop oscillation to measure surface tension and viscosity of molten samples was evaluated using Al2O3. Experimental results were consistent with the values measured with a ground-based electrostatic levitator as well as some data in literature, which proved that surface tension and viscosity could be measured by drop oscillation method in microgravity. This technique was then applied to molten terbium oxide (Tb2O3) whose surface tension and viscosity have not been reported. Measured surface tension could be expressed as γ(Τ) = 733.4-3.9x10-2(T-Tm) (10-3N/m), where Tm=2683 K and the viscosity as η(T)=0.33exp[9.75x104/(RT)] (10-3Pa·s) over the 2745 to 3259 K temperature span.

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By using the programming language C++ AMP, we have developed a new computational code working on GPU to be capable to compute incompressible free-surface flows including 6 DoF solid objects. The present computational code based on the CLSVOF method has been combined with an immersed boundary method to express and capture solid surfaces accurately. We have demonstrated several multiphase simulations such as binary collision of liquid drops in zero gravity field, a single rising bubble in a viscous liquid, a collapse of water column, milk coronet formation, and falling solid objects onto a liquid surface. The present code developed conserves the volume of each phase during the process of such complex flows and it exhibits the accurate estimation of the surface normal force. The computational results for the binary collision of liquid drops and the rising bubble in the viscous liquid have exhibited good agreement in comparison with the previous experimental results. The numerical results for the various multiphase flow phenomena have been successfully computed with relatively high speed owing to the appropriate combined computation between GPU and CPU, and visualized together with a ray-tracing technique to reproduce a kind of real flow phenomena.

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Based on previous research on the smallscale supersonic flight experiment vehicle’s liquid supplying system for bioethanol and LOX by pressurant gas, sloshing in the fuel tank has been shown to harm the flight of the vehicle by causing gas entrainment, which can fail the propulsion system. To solve this problem, we consider installing a device that can suppress the pressurant gas entrainment in the fuel tank. This device consists of a wire mesh that traps fuel in the supply duct by capillary force. In this study, this propellant management device (PMD) is examined based on the results of analysis and experiment. A liquid discharge experiment using the simulated propellant was carried out, as a performance verification of the PMD. This paper confirms the PMD’s performance in preventing the entrainment of gas and supplying fuel at a maximum liquid discharge flow rate of 0.6 L/s in an actual flight model.

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