Linear stability of two-dimensional flow in axisymmetric half-zones of low and intermediate prandtl numbers
| Autor: | Nienhueser, Ch., Kuhlmann, Hendrik C. |
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| Jazyk: | angličtina |
| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | 宇宙開発事業団技術報告: Marangoni Convection Modeling Research: Annual Report April 1, 2000 - March 31, 2001 = NASDA Technical Memorandum: Marangoni Convection Modeling Research: Annual Report April 1, 2000 - March 31, 2001. :181-208 |
| ISSN: | 1345-7888 |
| Popis: | The thermocapillary flow in liquid bridges is investigated numerically by means of a linear stability analysis. In the limit of large mean surface tension the free-surface shape is independent of the flow and temperature fields and depends only on the volume of liquid and the hydrostatic pressure difference. A differential heating of the bounding circular disks then causes a steady two-dimensional thermocapillary flow which is calculated by a finite-difference method on body-fitted coordinates. The linear-stability problem for the basic flow is solved using azimuthal normal modes computed with the same discretization method. The dependence of the critical Reynolds number on the volume fraction, gravity level, and aspect ratio is investigated for intermediate Prandtl numbers. The effect of gravity on the flow stability is compared for small (Pr = 0.02) and large Prandtl numbers. Since the instabilities for small and large Prandtl numbers are markedly different, the gravity forces lead to a different behavior. While the hydrostatic shape of the bridge is the most important gravity effect on the critical conditions for low-Prandtl-number flows, buoyancy is the dominating factor for the flow stability when the Prandtl number is high. In addition to these investigations, the linear stability for acetone and methanol half-zones including the effect of evaporative cooling is calculated and compared with experimental data. 資料番号: AA0032601007 レポート番号: NASDA-TMR-010015E |
| Databáze: | OpenAIRE |
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