This study set out to systematically investigate the structural characteristics of plane electrohydrodynamic jets through the particle image velocimetry (PIV) techniques. Due to the wide range of applied voltages and electrode gaps under various experimental conditions, an assessment of the image quality and a statistical analysis of the velocity fields are first performed to ensure the validity of the PIV measurements, which were originally applied purely to fluid mechanics. The results indicate that the time interval between two consecutive images should be pre-adjusted to reduce the number of uncorrelated vector fields. Moreover, the minimum number of instantaneous fields should be achieved for an accurate calculation of the time-averaged fields. An equivalent electric field criterion adapted to the asymmetric electrode configuration is defined to find similarities in flow structures under different voltage and electrode gap conditions. As the applied electric field increases, three injection regimes are identified and the current increases almost linearly, indicating a large conduction current component. The decrease in charge density due to recombination proves to be relevant in all cases of this study. Analogous to the parametric analysis approach for classical jets and thermal plumes, the evolution of the coefficients of axial velocity, half-width and turbulence intensity are investigated.

中文翻译：

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受高度不均匀电场影响的叶片平面致动器引起的电流体动力射流的结构特征：通过粒子图像测速技术进行参数研究

本研究旨在通过粒子图像测速 (PIV) 技术系统地研究平面电流体动力射流的结构特征。由于在各种实验条件下施加的电压和电极间隙范围很广，因此首先对图像质量进行评估和对速度场进行统计分析，以确保 PIV 测量的有效性，这些测量最初仅应用于流体力学. 结果表明，应预先调整两个连续图像之间的时间间隔，以减少不相关矢量场的数量。此外，为了准确计算时间平均场，应达到瞬时场的最小数量。定义了适用于不对称电极配置的等效电场准则，以发现不同电压和电极间隙条件下流动结构的相似性。随着施加电场的增加，确定了三种注入方式，电流几乎呈线性增加，表明存在较大的传导电流分量。事实证明，重组导致的电荷密度降低与本研究的所有情况都相关。类似于经典射流和热羽流的参数分析方法，研究了轴向速度、半宽度和湍流强度系数的演变。确定了三种注入方式，电流几乎呈线性增加，表明存在较大的传导电流分量。事实证明，重组导致的电荷密度降低与本研究的所有情况都相关。类似于经典射流和热羽流的参数分析方法，研究了轴向速度、半宽度和湍流强度系数的演变。确定了三种注入方式，电流几乎呈线性增加，表明存在较大的传导电流分量。事实证明，重组导致的电荷密度降低与本研究的所有情况都相关。类似于经典射流和热羽流的参数分析方法，研究了轴向速度、半宽度和湍流强度系数的演变。