Instability mechanisms of thermocapillary liquid bridges between disks of unequal radii
Instability mechanisms of thermocapillary liquid bridges between disks of unequal radii
复制标题
不等半径圆盘间热毛细管液桥的不稳定机制
DOI：
10.1063/5.0120825
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发表时间：
2022
影响因子：
4.6
通讯作者：
Linmao Yin
中科院分区：
文献类型：
--
作者：
Haogyi Li;Z. Zeng;Liang Zhang;Hao Liu;Yong Liu;Yue Wang;Yao Xiao;Linmao Yin
在本文中，我们探讨了两个磁盘之间的热毛细液体桥的半径不相等的普朗特数Pr为0.0258（汞）和0.068（砷化镓），以深入了解潜在的不稳定机制。在勒让德谱元法的框架下，通过线性稳定性分析确定了临界条件，然后通过能量分析确定了失稳机制。为了水星大桥（Pr=0.0258），我们的分析表明，流动不稳定性经历了振荡分岔的半径比范围内的0.5{小于或等于} r{小于或等于}0.66，而当半径比进一步增大到0.73时，可以产生三个二维定常轴对称流和三维定常流之间的过渡。小于或等于} r{小于或等于}0.76。对于砷化镓液桥（Pr=0.068），在整个计算区间内，不稳定性始终是一个振荡分岔。此外，我们的观察确定了六种不同机制的不稳定模式。汞桥（Pr=0.0258）中的所有不稳定模式都是纯流体动力学的，但由于Pr效应的增强，砷化镓液桥（Pr=0.068）中的热毛细机制不能忽略。
In this paper, we explore the thermocapillary liquid bridge between two disks of unequal radii with Prandtl numbers Pr of 0.0258 (mercury) and 0.068 (gallium arsenide) to gain insights into the underlying instability mechanism. In the context of Legendre's spectral element method, we determine the critical conditions via linear stability analysis, and then identify the instability mechanism through energy analysis. For the mercury bridge ( Pr=0.0258), our analysis suggests that the flow instability undergoes an oscillatory bifurcation for radius ratios in the range 0.5{less than or equal to} Γr{less than or equal to}0.66, whereas three transitions between two-dimensional steady axisymmetric flow and three-dimensional stationary flow can be produced by further increasing the radius ratio to 0.73{less than or equal to} Γr{less than or equal to}0.76. For the gallium arsenide liquid bridge ( Pr=0.068), the instability is always an oscillatory bifurcation in the whole computational interval. Furthermore, our observations identify six instability modes with different mechanisms. All instability modes in the mercury bridge ( Pr=0.0258) are purely hydrodynamic, but the thermocapillary mechanism cannot be ignored in the gallium arsenide liquid bridge ( Pr=0.068) because of the enhanced Pr effect.