Thermal convection in a cylindrical annulus under a combined effect of the radial and vertical gravity

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• 作者：Antoine Meyer^a ; Marcel Jongmanns^b ; Martin Meier^b ; Christoph Egbers^b ; Innocent Mutabazi^a ; ^{innocent.mutabazi@univ-lehavre.fr}
• 关键词：Thermal convection ; Cylindrical annulus ; Dielectrophoretic buoyancy ; Electric gravity ; Thermal modes ; Electric modes ; Columnar modes ; Microgravity ; Parabolic flight experiment
• 刊名：Comptes Rendus Mécanique
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：345
• 期：1
• 页码：11-20
• 全文大小：1591 K
• 卷排序：345

文摘

The stability of the flow of a dielectric fluid confined in a cylindrical annulus submitted to a radial temperature gradient and a radial electric field is investigated theoretically and experimentally. The radial temperature gradient induces a vertical Archimedean buoyancy and a radial dielectrophoretic buoyancy. These two forces intervene simultaneously in the destabilization of the flow, leading to the occurrence of four types of modes depending on the relative intensity of these two buoyancies and on the fluid's properties: hydrodynamic and thermal modes that are axisymmetric and oscillatory, stationary columnar modes and electric modes which are stationary and non-axisymmetric modes. Experiments performed in a parabolic flight show the existence of non-axisymmetric modes that should be either columnar or helicoidal vortices.