航空機を用いた微小重力環境下での電磁浮遊法による高温融体熱物性値計測

摘要

Microgravity conditions have advantages of measurement of the surface tension and the viscosity of metallic alloys by the oscillating drop method with an electromagnetic levitation (EML) device. Since under microgravity conditions the surface oscillation spectra has a single peak and an exponential decay of the surface oscillations, we can obtain the surface tension and the viscosity by analyzing the surface oscillation spectra. However, the surface oscillation spectra has many peaks in sometimes even under microgravity conditions. This is due to modulation of surface oscillation by the sample rotation. From the modulation of the surface oscillation, precise measurements of the surface tension and the viscosity are difficult. In order to obtain the precise surface tension and viscosity from the surface oscillation spectra modulated by the sample rotation, we propose an improved analysis of the surface oscillation spectra of electromagnetically levitated liquid droplet under microgravity conditions. We try to measure the precise surface tension and viscosity by the proposed analytical technique with the measured surface oscillation spectra obtained under microgravity conditions by the airplane parabolic flight. This approach is relevant for high temperature, reactive alloys such as Ti based alloys which can not be measured by the sessile and oscillating or rotating cup method.%以上で述べた新しい表面振動の本手法の確立が達成できれば，Ti系合金などこれまでの測定例がない物質についての測定も可能となる.今年度において,JAXA保有の航空機搭載用電磁浮遊装置PFLEXを用い航空機による微小重力での電磁浮遊実験をおこない電磁浮遊液滴の表面振動を計測し，上記で述べた方法で表面張力と粘性を求め計画である.さらに，雰囲気酸素分圧の表面張力依存性を調べるために，酸素分圧を制御したガスボンベを用意し，これを航空機へ搭載し，PFLEXへ接続する.