Niazi Muhammad Shaheer
Lahore College of Arts and Sciences, Lahore, Punjab, Pakistan.
R Soc Open Sci. 2017 Oct 4;4(10):170503. doi: 10.1098/rsos.170503. eCollection 2017 Oct.
The Rose window instability is a little-explored electrohydrodynamic instability that manifests when a layer of low-conducting oil is placed in an electric field generated by corona discharge in a point-to-plane configuration. Above a critical voltage, the instability starts as a single dimple in the oil layer right below the point electrode and subsequently evolves into a characteristic pattern of polygonal cells. In this study, we experimentally explore governing parameters that guide the instability and document geometric attributes of the characteristic cellular pattern. The driving force for the instability has been attributed to the buildup of charged ions which in turn apply an electric pressure on the oil surface. We confirm the charged surface distribution using thermal imaging and demonstrate that the instability can be locally inhibited by preventing charge buildup under an ion shadow.
玫瑰窗不稳定性是一种研究较少的电流体动力学不稳定性，当一层低导电率油置于点-面配置的电晕放电产生的电场中时就会出现这种不稳定性。在临界电压以上，不稳定性始于点电极正下方油层中的单个凹痕，随后演变成多边形单元的特征图案。在本研究中，我们通过实验探索了引导不稳定性的控制参数，并记录了特征细胞图案的几何属性。不稳定性的驱动力归因于带电离子的积累，这些离子进而对油表面施加电压力。我们使用热成像确认了带电表面分布，并证明通过防止离子阴影下的电荷积累，可以局部抑制不稳定性。
