Ionic wind velocity and energy efficiency improvement in needle-net ionic wind generator by electrical field optimization

Abstract

Ionic wind produced by high voltage discharge has been proved as a promising technique in heat dissipation, food drying, electrostatic precipitation and air propulsion. On the other hand, the low wind velocity and the low energy efficiency of the ionic wind generators limit their performance in practical industrial applications. To improve this, a single needle-net electrode structure ionic wind generator driven by positive DC voltage is constructed and the effects of the applied voltage and the needle-net distance on the discharge characteristics have been investigated. The results show that with the increase of the applied voltage from 4 kV to 11 kV, the discharge shows four stages, burst pulse, streamer corona, glow corona and spark discharge, and the wind velocity increases monotonously and reach 1.90 m/s at 11 kV. At the same applied voltage, the shorter needle-net distance leads to the larger wind velocity. At 15 mm needle-net distance, the needle-net electrode structure ionic wind generator shows a maximum energy efficiency value of 2.19%. A metal circular plate is attached on the needle electrode to enhance the electric field in discharge spacing. It is found that the wind velocity and energy efficiency can be improved from 1.90 m/s to 2.35 m/s, and 1.87% to 3.14%, at same applied voltage and needle-net distance. The cooling experiment shows that the ionic wind generator with metal circular plate needle-net electrode has better heat dissipation effect.

The heat dissipation by the multi-needle electrode structure ionic wind generator

“…where U ¢ and I¢ are the drive voltage and the drive current of MOSFET, which are 12 V and 1 A, h¢ is the component heating efficiency. In order to maximize the heating power and measure the heat dissipation performance, h¢ is set as 80% here according to references [31,32]. R th,j c -is the thermal resistance and is 1.5 K W −1 , which represents the heat transfer capacity between the media.…”

“…In previous studies, we investigated the discharge characteristics of a single-needle-net electrode structure plasma actuator [32]. Along with increasing of the applied voltage, the gas near the needle tip would be ionized first with enough electric field strength and the discharge would experience initial corona, glow corona, streamer discharge, and spark four stages [33].…”