Abstract Experiments on the electrohydrodynamic (EHD) flow characteristics of a dielectric liquid in a sharp needle-plate configuration under direct current (DC) and alternating current (AC) electric field are carried out. The current-voltage characteristics and the velocity field are simultaneously recorded for understanding the flow behavior and its mechanism. For the DC case, a critical voltage separating the conduction and injection regimes and the corresponding flow reverse is observed. Results indicate the polarity of voltage only influences the flow's intensity in the injection regime. For the AC case, two types of signals with the same 50% duty cycle are considered. For the pulsed voltage (−2.0kV to 0), the flow generally keeps the plume structure and shows weaker strength than the corresponding DC case. For the AC signal (-2.0kV–+2.0kV), the velocity amplitude first decreases and then tends to be constant with the increase of frequency. The weak flow motion with high frequency AC field is due to conduction.

中文翻译：

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直流/交流电场下针板结构电介质液体电流体动力学流动的实验研究

摘要 在直流 (DC) 和交流 (AC) 电场下，对尖锐针板结构的介电液体的电流体动力学 (EHD) 流动特性进行了实验。同时记录电流-电压特性和速度场，以了解流动行为及其机制。对于直流情况，观察到一个临界电压将传导和注入状态分开，并观察到相应的反向流动。结果表明电压的极性仅影响注射状态下的流动强度。对于 AC 情况，考虑了具有相同 50% 占空比的两种类型的信号。对于脉冲电压（-2.0kV 到 0），流动一般保持羽状结构，强度比相应的直流情况弱。对于交流信号 (-2.0kV–+2. 0kV)，速度幅值随着频率的增加先减小后趋于恒定。高频交流场的微弱流动运动是由于传导。