7th Asia-Pacific Conference on Plasma Physics, 12-17 Nov, 2023 at Port Messe Nagoya

Study on the characteristics of long-distance negative corona ionic wind byneedle to mesh electrodes

Huan Chen1, Shuai Yang1, Yong Yang1, Chuan Li1
1
State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong
University of Science and Technology
e-mail (speaker): 3106907727@qq.com
When a high voltage is applied to two asymmetricelectrode structures to generate a corona discharge, theions generated by air ionization near the electrode with asmaller curvature radius move and collide with air
molecules under the action of an electric field and transfer
momentum to cause air flow, which is called ionic wind.
Ionic wind is widely used in cooling [1], dust removal [2],drying [3] and other fields due to its advantages of norotating parts, no noise, and low energy consumption.
Recently, many research groups have studied the initiationand temporal process of ionic wind [4], the cooling and gas
transmission performance of ionic wind [5] and so on.
However, their research mainly focused on various
characteristics of the short-distance ionic wind, and thedischarge distance rarely exceeds 5 cm. The ionic windunder the long distance is more conducive to theapplication of large-scale electrostatic dust removal andcooling. Therefore, it is necessary to study the longdistance ionic wind.
This article studies the ionic wind with a spacing of 10
cm between the needle and the mesh. A high voltage of 10 kV is applied to the needle electrode, and the meshelectrode is grounded. The ionic wind traced by thedroplet is photographed with a high-speed camera, and theflow field of the ionic wind is processed by particle image
velocimetry (PIV) technology. Figure 1 shows the initial
evolution process of the -10 kV ionic wind. The brighter
area in the image corresponds to a higher concentration oftracer particles, and the black area indicates a lower
concentration or absence of tracer particles. There is along and narrow dark area directly below the needle tip,indicating that the ionic wind is generated at the needle tip.
The ionic wind moves from the needle electrode to themesh electrode, and the head of the ionic wind is "Ushaped". Figure 2 shows the velocity flow field at
different times during the initial evolution of -10 kV ionicwind processed by PIV technology. PIV technology canmeasure the velocity flow field and other velocity
information of ionic wind without disturbing the flow
field. At the time of 200 ms, 400 ms and 600 ms, themaximum wind velocity appears at 0.5 cm ≤ y ≤ 1.5 cm,
1 cm ≤ y ≤ 2cm and 4 cm ≤ y ≤ 5 cm. With the evolutionof the ionic wind, the area where the maximum velocity
appears gradually approaches the mesh electrode. At thetime of 200 ms, 400 ms and 600 ms, the range of jet withionic wind velocity exceeding 0.1 m/s is -0.5 cm ≤ x ≤ 0.5cm, 1 cm ≤ x ≤ 1cm and -1.5 cm ≤ x ≤ 1.5 cm. The
maximum velocity of ionic wind and the range of jet flow
increase with time.
This work is supported by National Natural Science
Foundation of China (Grant No. 52207158).
References[1] J. Qu et al, Appl. Therm. Eng. 193, 116946 (2021)[2] L. Chen et al, Sep. Purif. Technol. 247, 116964 (2020)[3] T. Defraeye et al, J. Food Eng. 240, 38–42 (2019)[4] Y. Yang et al, IEEE Trans. Plasma Sci. 51(2), 352–358(2023)[5] X. Ren et al, Int. J. Heat Mass Transf. 200, 123539(2023)

Figure 1. -10 kV corona ionic wind initial evolution process at (a) t = 200 ms, (b) t = 400 ms and (c) t = 600 ms.

Figure 2. -10 kV corona ionic wind velocity flow field at (a) t = 200 ms, (b) t = 400 ms and (c) t = 600 ms.