On the stabilizing effect of a liquid film on a cylindrical core by oscillatory motions
On the stabilizing effect of a liquid film on a cylindrical core by oscillatory motions
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DOI：
10.1063/1.4863846
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发表时间：
2014-02
影响因子：
4.6
通讯作者：
W. Rohlfs;M. Binz;R. Kneer
中科院分区：
文献类型：
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作者：
W. Rohlfs;M. Binz;R. Kneer
如果圆柱体（如金属丝或纤维）上的液膜长度超过临界尺寸，则液膜会破裂（Plateau-Rayleigh不稳定性）。只要给定一个适当的强迫振幅和频率的组合，固体核的轴向振荡就可以实现稳定。为了研究稳定效果，使用基于高度函数的求解器对轴对称问题进行了直接数值模拟（DNS）。结果表明，膜稳定化的机理是由惯性主导区（高膜厚）和粘度主导区（低膜厚）之间的相互作用引起的。从而支持薄膜区域的补充，同时抑制耗尽，最终导致振荡圆筒上的稳定膜流。最后，主要系统参数的系统变化，例如，给出了韦伯数、内核半径与平均膜厚之比、振荡频率等参数的变化规律。
Liquid films on cylindrical bodies like wires or fibres disintegrate if their length exceeds a critical size (Plateau-Rayleigh instability). Stabilization can be achieved by an axial oscillation of the solid core provided that a suitable combination of forcing amplitude and frequency is given. To investigate the stabilizing effect, direct numerical simulations (DNS) of the axisymmetric problem are conducted with a height function based solver. It is found that the mechanism of film stabilization is caused by the interaction between an inertia dominated region (high film thickness) and a viscosity dominated region (low film thickness). Replenishing of the thin film region is thereby supported while depleting is suppressed, finally leading to a stable film flow on an oscillating cylinder. To the end, a systematic variation of the main system parameters, e.g., the Weber number, the ratio between the radius of the inner core and the average film coating thickness, and the oscillation frequency is presented an...