The wetting and contact line dynamics of a leaky dielectric sessile droplet under an alternating (ac) electrostatic field applied in the vertical direction is investigated. A thin precursor film-based reduced-order model using the weighted residual integral boundary layer technique is developed. The limiting cases of perfect conducting and perfect dielectric droplets are also considered. It is shown that the droplet oscillates with a frequency twice that of the forcing potential due to the quadratic dependence of the Maxwell stress on the applied ac electric field. These oscillations take place about an equilibrium configuration, which can be achieved with a constant (dc) electric potential equivalent to the root-mean-square potential of the applied ac field. It is also shown that the contact line motion increases monotonically with the amplitude of the ac electric forcing. A significant increase in ac field leads to spiking and the interface ruptures at the top electrode. Depending on the static contact angle, the droplet deformation can become nonmonotonic as the applied frequency of the ac electric field increases. This behavior is attributed to the competition between the timescale of forcing and the timescale of the response as affected by the drop's wettability. The role of conductivity ratio, permittivity ratio, and different waveforms of ac forcing are also investigated.

中文翻译：

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时间周期电场下漏电介质液滴的电润湿

研究了在垂直方向施加的交变 (ac) 静电场下漏电介质固着液滴的润湿和接触线动力学。开发了使用加权残余积分边界层技术的基于薄前体膜的降阶模型。还考虑了完美导电和完美电介质液滴的极限情况。结果表明，由于麦克斯韦应力对施加的交流电场的二次依赖性，液滴以两倍于强迫电位的频率振荡。这些振荡发生在平衡配置附近，这可以通过恒定 (dc) 电势实现，该电势等于施加的交流场的均方根电势。还表明接触线运动随着交流电力的幅度单调增加。交流场的显着增加会导致尖峰信号和顶部电极处的界面破裂。根据静态接触角，随着交流电场施加频率的增加，液滴变形可能变得非单调。这种行为归因于受液滴润湿性影响的强迫时间尺度和响应时间尺度之间的竞争。还研究了电导率比、介电常数比和不同的交流强迫波形的作用。随着交流电场频率的增加，液滴变形会变得非单调。这种行为归因于受液滴润湿性影响的强迫时间尺度和响应时间尺度之间的竞争。还研究了电导率比、介电常数比和不同的交流强迫波形的作用。随着交流电场频率的增加，液滴变形会变得非单调。这种行为归因于受液滴润湿性影响的强迫时间尺度和响应时间尺度之间的竞争。还研究了电导率比、介电常数比和不同的交流强迫波形的作用。