Dual-pin electrohydrodynamic generator driven by alternating current

• Published in: Experimental thermal and fluid science 2018-10, Vol.97, p.290-295
• Main Authors: Dau, Van Thanh, Dinh, Thien Xuan, Tran, Canh-Dung, Terebessy, Tibor, Bui, Tung Thanh
• Format: Article
• Language: English
• Subjects: AC generators; Air flow; Alternating current; Bipolar discharge; Circuit design; Configurations; Direct current; Electric fields; Electric potential; Electrodes; Electrohydrodynamics; Fluid mechanics; Generators; High voltage; High voltages; Impurities; Ion wind; Ions; Parallel pin; Robust design; Tips; Tolerances; Voltage; Wind power
• ISSN: 0894-1777; 1879-2286
• DOI: 10.1016/j.expthermflusci.2018.04.028

Ion wind velocity at time 0.02 ms after switching the polarity of electrodes. [Display omitted] •Alternating current (AC) driven corona based air-flow generator using symmetrically arranged electrodes was studied.•When the AC frequency exceeds a threshold value, the electrode gap is less critical and stronger ion wind is achieved.•The electric field is enhanced by AC driven system.•Transient simulation by OpenFOAM demonstrates the effect of space charge. We report a unique alternating current (AC) driven corona based air-flow generator using symmetrically arranged electrodes. Unlike the conventional configuration where one electrode generates charged ions moving towards the reference electrode, this configuration allows both negative and positive charges to simultaneously move away from the device and generate ion wind in parallel with the electrodes. In comparison with the direct current (DC) driven corona generator, the time oscillating AC field allows the device a better stabilization owing to the independence of ion wind strength from the inter-electrode spacing. Our results by both simulation and experiment showed that when the AC frequency exceeds a threshold value of 1100 Hz, the electric field at the electrode tips is determined dominantly by the charge cloud created in the previous half-cycle, resulting in stronger net electric field and thus stronger ion wind. In addition, the electrode separation in the AC driven corona based generator is less critical above the frequency threshold, yielding a more robust design with minimized susceptibility to manufacturing tolerances and impurities on the electrodes. Moreover, lower voltage levels of the AC driven system allow simpler and more economical design in the high voltage circuit of the AC generator.