TWO BIFURCATION TRANSITION PROCESSES IN FLOATING HALF ZONE CONVECTION OF LARGER PRANDTL NUMBER FLUID

【摘要】 <正> Processes of the onset oscillation in the thermocapillary convectionunder the Earth’s gravity are investigated by the numerical simulation and exper-iments in a floating half zone of large Prandtl number with different volume ratio.Both computational and experimental results show that the steady and axisymmetricconvection turns to the oscillatory convection of m=l for the slender liquid bridge,and to the oscillatory convection before a steady and 3D asymmetric state for thecase of a fat liquid bridge.It implies that,there are two critical Marangoni numbersrelated,respectively,to these two bifurcation transitions for the fat liquid bridge.Thecomputational results agree with the results of ground-based experiments.更多还原

【Abstract】 Processes of the onset oscillation in the thermocapillary convection under the Earth’s gravity are investigated by the numerical simulation and exper- iments in a floating half zone of large Prandtl number with different volume ratio. Both computational and experimental results show that the steady and axisymmetric convection turns to the oscillatory convection of m=l for the slender liquid bridge, and to the oscillatory convection before a steady and 3D asymmetric state for the case of a fat liquid bridge.It implies that,there are two critical Marangoni numbers related,respectively,to these two bifurcation transitions for the fat liquid bridge.The computational results agree with the results of ground-based experiments.更多还原