Plasma synthetic jet actuator(PSJA) has a wide application prospect in the high-speed flow control field for its high jet velocity.In this paper,the influence of the air pressure on the performance of a two-electrod...Plasma synthetic jet actuator(PSJA) has a wide application prospect in the high-speed flow control field for its high jet velocity.In this paper,the influence of the air pressure on the performance of a two-electrode PSJA is investigated by the schlieren method in a large range from 7 k Pa to 100 k Pa.The energy consumed by the PSJA is roughly the same for all the pressure levels.Traces of the precursor shock wave velocity and the jet front velocity vary a lot for different pressures.The precursor shock wave velocity first decreases gradually and then remains at 345 m/s as the air pressure increases.The peak jet front velocity always appears at the first appearance of a jet,and it decreases gradually with the increase of the air pressure.A maximum precursor shock wave velocity of 520 m/s and a maximum jet front velocity of 440 m/s are observed at the pressure of 7 k Pa.The averaged jet velocity in one period ranges from 44 m/s to 54 m/s for all air pressures,and it drops with the rising of the air pressure.High velocities of the precursor shock wave and the jet front indicate that this type of PSJA can still be used to influence the high-speed flow field at 7 k Pa.展开更多
The resistance of Ionic Polymer Metal Composite (IPMC) electrodes plays an important role in the actuation performance of IPMC actuators. Owing to crack formation on the surface of platinum electrode, the surface re...The resistance of Ionic Polymer Metal Composite (IPMC) electrodes plays an important role in the actuation performance of IPMC actuators. Owing to crack formation on the surface of platinum electrode, the surface resistance of the electrode increases, which greatly limits its actuating performance. In this paper, we proposed a new method of dynamic self-repair electrodes by ex- changing Cu2+ into the IPMC basement membrane. IPMC actuators with Cu2+ were prepared and the actuation performance in the air was subsequently measured. Compared with conventional IPMC actuators containing Li+ counter ions, those containing Cu2+ counter ions exhibited 2 times - 3 times larger displacement and 2 times -3 times bigger blocking force. In the morphology observation, we found that many small copper particles scattered in the middle of cracks after several bending cycles, which leads to an obvious decrease in electrode resistance. In the Cyclic Voltammetry (CV) scan measurement, we observed that the oxidation reaction of copper alternates with reduction reaction of copper ions with the change of voltage polarity, which was a dynamic process. Based on these analyses, it is concluded that the presence of Cu2+ can repair the damaged electrodes and induce lower electrode resistance, thus leading to the performance improvement of actuation.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51407197,51522606,51336011,91541120,and 11472306)
文摘Plasma synthetic jet actuator(PSJA) has a wide application prospect in the high-speed flow control field for its high jet velocity.In this paper,the influence of the air pressure on the performance of a two-electrode PSJA is investigated by the schlieren method in a large range from 7 k Pa to 100 k Pa.The energy consumed by the PSJA is roughly the same for all the pressure levels.Traces of the precursor shock wave velocity and the jet front velocity vary a lot for different pressures.The precursor shock wave velocity first decreases gradually and then remains at 345 m/s as the air pressure increases.The peak jet front velocity always appears at the first appearance of a jet,and it decreases gradually with the increase of the air pressure.A maximum precursor shock wave velocity of 520 m/s and a maximum jet front velocity of 440 m/s are observed at the pressure of 7 k Pa.The averaged jet velocity in one period ranges from 44 m/s to 54 m/s for all air pressures,and it drops with the rising of the air pressure.High velocities of the precursor shock wave and the jet front indicate that this type of PSJA can still be used to influence the high-speed flow field at 7 k Pa.
基金The authors gratefully acknowledge financial support from the Joint Funds of the National Natural Science Foundation of China (U1637101) and NSFC (51605220 and 51175251), Natural Science Foundation of Jiangsu Province (BK20160793), the Open Project Fund in Jiangsu Provincial Key Laboratory for Interventional Medical Devices (jr1601), the Open Project Fund in Hubei Key Laboratory of Hydroelectric Ma- chinery Design & Maintenance (2017KJX 11). This is a project funded by the Priority Academic Program De- velopment of Jiangsu Higher Education Institutions (PAPD), Shanghai Key Laboratory of Spacecraft Mechanism and Science and Technology Commission of the Military Commission. Special thanks to Andrew Jackson, PhD, for editing the English text of a draft of this manuscript.
文摘The resistance of Ionic Polymer Metal Composite (IPMC) electrodes plays an important role in the actuation performance of IPMC actuators. Owing to crack formation on the surface of platinum electrode, the surface resistance of the electrode increases, which greatly limits its actuating performance. In this paper, we proposed a new method of dynamic self-repair electrodes by ex- changing Cu2+ into the IPMC basement membrane. IPMC actuators with Cu2+ were prepared and the actuation performance in the air was subsequently measured. Compared with conventional IPMC actuators containing Li+ counter ions, those containing Cu2+ counter ions exhibited 2 times - 3 times larger displacement and 2 times -3 times bigger blocking force. In the morphology observation, we found that many small copper particles scattered in the middle of cracks after several bending cycles, which leads to an obvious decrease in electrode resistance. In the Cyclic Voltammetry (CV) scan measurement, we observed that the oxidation reaction of copper alternates with reduction reaction of copper ions with the change of voltage polarity, which was a dynamic process. Based on these analyses, it is concluded that the presence of Cu2+ can repair the damaged electrodes and induce lower electrode resistance, thus leading to the performance improvement of actuation.