A review on recent advances and challenges of ionic wind produced by corona discharges with practical applications

Ionic wind, an induced phenomenon during corona discharge, possessing the features of silent operation and no moving parts, has a wide range of applications. Ionic wind generation is accompanied by complex physical processes, involving gas ionization, ion recombination, flow, and various chemical reactions, as well as mutual couplings between some of them. Therefore, understanding the corona discharge process and ionic wind generation is crucial for researchers and engineers to better utilize this phenomenon in practical applications. In this review, the principles of corona discharge and its induced ionic wind are presented. Subsequently, ionic wind generators (IWGs) are discussed according to their applications, and the corresponding advances based on experimental studies and numerical simulations are also reviewed. Moreover, the challenges of transitioning the ionic wind technology from laboratory studies to practical applications are discussed. These challenges include the excessively high onset voltage of the corona, ozone emission, and influence of environmental conditions. Furthermore, the mechanisms of these barriers and several effective approaches for mitigating them are provided. Finally, some future research prospects and the conclusions are presented.

Research on characteristics of dual-frequency coupling electroaerodynamic thruster

Breaking through the corona discharge current limit and improving the ionization and acceleration process are beneficial to improve the performance of the electroaerodynamic thruster. In this paper, a dual-frequency source of DC and NSP (nanosecond pulse) are applied to generate ionic wind. Electrical, optical and thrust characteristics are compared for the electroaerodynamic thruster with and without the NSPD (nanosecond pulse discharge). The experimental results indicate that the thrust characteristics are enhanced under the effect of dual-frequency sources. Moreover, the inception DC voltage to generate ionic wind is much lower.

Spectral Characteristics of Needle Array-Plate Dielectric Barrier Discharge Plasma and Its Activated Water

The plasma-activated water (PAW), as a new environmentally friendly nonthermal processing technology, has attracted wide attention for its applications in agriculture, food, and biomedical fields. This paper used the needle array-plate dielectric barrier discharge (needle array-plate DBD) device to activate deionized water and prepare PAW simply and efficiently. It was found that the concentration of reactive oxygen and nitrogen species (RONS) generated in the process of needle array-plate DBD was large and varied. Especially in the wavelength range of 600–770 nm, the spectral intensity is stronger. And, the ionic wind is more likely to interact with the deionized water. The changes in PAW parameters and UV/Vis spectra with treatment time were measured under different voltages and needle-dielectric plate distances. Results show that increasing discharge voltage or decreasing needle-dielectric plate distance increases the concentration of RONS, ionic wind speed, water evaporation, and conductivity of the PAW and decreases pH. UV/Vis spectra results show that prolonged treatment time results in increased total absorbance and concentrations of H2O2 and NO 3 − and that a new absorption peak appears at 210 nm in the UV/Vis spectra. When the wavelength is larger than 210 nm, a redshifted new peak and color enhancement are observed. The seeds of Astragalus adsurgens Pall were treated by discharge plasma, PAW, and the combination of plasma and PAW. It was found that high voltage and long-time activated PAW could significantly increase the ROS level of seeds and seedlings after germination for 3 days, resulting in oxidative stress damage. The survival rate of seeds was lower than that under the half lethal dose. This paper provides a feasible device design for treating activated water in large quantities with high efficiency, which is important for the application of PAW and mutation breeding of A. adsurgens Pall.

The Effects of Inlet Blockage and Electrical Driving Mode on the Performance of a Needle-Ring Ionic Wind Pump

The thermal management of microelectronics is important because overheating can lead to various reliability issues. The most common thermal solution used in microelectronics is forced convection, which is usually initiated and sustained by an airflow generator, such as rotary fans. However, traditional rotary fans might not be appropriate for microelectronics due to the space limit. The form factor of an ionic wind pump can be small and, thus, could play a role in the thermal management of microelectronics. This paper presents how the performance of a needle-ring ionic wind pump responds to inlet blockage in different electrical driving modes (direct current), including the flow rate, the corona power, and the energy efficiency. The results show that the performance of small needle-ring ionic wind pumps is sensitive to neither the inlet blockage nor the electrical driving mode, making needle-ring ionic wind pumps a viable option for microelectronics. On the other hand, it is preferable to drive needle-ring ionic wind pumps by a constant current if consistent performance is desired.