並列タイトル等中間プラントル数の液体ブリッジにおける振動マランゴニ対流への転移
タイトル（掲載誌）宇宙開発事業団技術報告: Marangoni Convection Modeling Research: Annual Report April 1, 1999 - March 31, 2000 = NASDA Technical Memorandum: Marangoni Convection Modeling Research: Annual Report April 1, 1999 - March 31, 2000
一般注記Marangoni convection experiments have been conducted with acetone (Pr = 4.3) and methanol (Pr = 6.8) liquid bridges to investigate the flow structures and temperature fields during transition from steady to oscillatory convection in a half floating zone. The disk diameters of 5.0 mm and 10.0 mm were used for both fluids and the liquid bridge height was changed from 1.5 mm to 4.5 mm, covering aspect ratios from 0.3 up to 1.6. Various advanced measurement techniques were employed to yield detailed experimental data useful for both understanding the mechanism responsible for transition as well as verifying linear stability analysis and three-dimensional numerical simulation predictions. In order to reduce the surface evaporation rate, a quartz tube was fitted around the liquid bridge for both fluids. The liquid bridge shape data were obtained for both fluids covering a wide range of volume ratios for each aspect ratio and disk diameter. For acetone, the transition from steady to oscillatory convection was found to occur at disk temperature differences of 1.3 to 2.3 K, and liquid temperature fluctuations with amplitudes of 0.02 to 0.1 K were detected. For methanol, oscillatory flow appeared at disk temperature differences ranging from 1.6 to 4.3 K. For acetone, the transition was also accompanied by the appearance of an azimuthal component of surface velocity. At the same time, the toroidal vortex started to expand and contract in size, and the radial flow field started to rotate. Although the surface displacement was measured, surface oscillations could not be detected probably because of an insufficient driving force arising from small temperature differences. The critical Marangoni numbers for acetone were found to be higher than the values extrapolated from existing data, due to the effects of evaporation and added heat loss from the liquid surface. On the other hand, the critical Marangoni numbers for methanol showed good agreement with the existing data for a similar Prandtl number.
資料番号: AA0010763003
レポート番号: NASDA-TMR-000006E
一次資料へのリンクURLhttps://jaxa.repo.nii.ac.jp/?action=repository_action_common_download&item_id=41247&item_no=1&attribute_id=31&file_no=1
連携機関・データベース国立情報学研究所 : 学術機関リポジトリデータベース（IRDB）（機関リポジトリ）
提供元機関・データベース宇宙航空研究開発機構 : 宇宙航空研究開発機構リポジトリ