Abstract In this study, the visualization of the flow inside a Taylor cone formed during an electrohydrodynamic (EHD) spraying is conducted to analyze its stability among five liquid candidates. A micro-PIV with a micro-nozzle is used for the visualization, and the physical properties as well as measured values are utilized in the analysis. First, in forming the Taylor cone, the electrohydrodynamic force is required to be sufficiently large in order to overcome the surface tension of the liquid. Thus, among the five liquids tested here, three, in this case IPA, EtOH, and MeOH, form a Taylor cone due to the relatively low surface tension levels as compared to the others. Once electrohydrodynamic jetting occurs, the average and maximum velocities become monotonically proportional to the average current. As the velocities are the smallest in using IPA, the circulation flow becomes superior to the extrusive flow, which yields the stable formation of a Taylor cone. Also, low fluctuation of the instantaneous currents supports the stable formation of IPA. Consequently, IPA shows the most stable formation of the Taylor cone in our condition due to the lowest average current and low-level surface tension. Eventually, micro-PIV would be a good tool in choosing an optimal fluid for stable EHD spraying. Graphic abstract

中文翻译：

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基于微PIV测量的稳定泰勒锥地层流体选择实验研究

摘要 在这项研究中，对电流体动力 (EHD) 喷涂过程中形成的泰勒锥内部的流动进行了可视化，以分析其在五种候选液体中的稳定性。带有微型喷嘴的微型 PIV 用于可视化，并在分析中利用物理特性和测量值。首先，在形成泰勒锥时，电流体动力需要足够大以克服液体的表面张力。因此，在此处测试的五种液体中，三种（在这种情况下为 IPA、乙醇和甲醇）由于与其他液体相比具有相对较低的表面张力水平而形成泰勒锥。一旦电流体动力喷射发生，平均和最大速度变得与平均电流单调成比例。由于使用 IPA 时速度最小，循环流变得优于挤出流，从而稳定地形成泰勒锥。此外，瞬时电流的低波动支持 IPA 的稳定形成。因此，由于最低的平均电流和低水平的表面张力，IPA 在我们的条件下显示出最稳定的泰勒锥形成。最终，微型 PIV 将成为选择用于稳定 EHD 喷涂的最佳流体的好工具。图形摘要 由于最低的平均电流和低水平的表面张力，IPA 显示在我们的条件下泰勒锥的形成最稳定。最终，微型 PIV 将成为选择用于稳定 EHD 喷涂的最佳流体的好工具。图形摘要 由于最低的平均电流和低水平的表面张力，IPA 显示在我们的条件下泰勒锥的形成最稳定。最终，微型 PIV 将成为选择用于稳定 EHD 喷涂的最佳流体的好工具。图形摘要