Ionic Wind Generator Research Articles

Electromagnetic plasma micro actuator for active airflow control

This study presents a novel electromagnetic plasma micro actuator capable of generating ionic wind at an extremely low voltage. Ionic and electron movements, driven by the Lorentz force, introduce a lateral injection of initiation carriers, resulting in a significant reduction in discharge onset voltage. Straight ionic wind was demonstrated using a tapered gap electrode, which allowed continuous movement of plasma filament along the electrode at the speed of 4m/s when a DC pulse of 900V was applied. The results suggest that the proposed device may address key challenges faced by current ionic wind generators, such as high voltage requirements and limited device lifespans. In addition, a notable change in the airflow was observed when the direction of ionic wind was altered, indicating the feasibility of active airflow control with stable plasma formation and fast response times.

Development and numerical optimization of a cylindrical wire-fin-type integrated ionic wind heat sink for cooling high-power LEDs

Light-emitting diodes (LEDs) are becoming increasingly high-power and compact, which makes rotary fans incompetent in some cooling situations. The ionic wind technique can compensate for the shortcomings of rotating fans, owing to its benefits of no moving parts and compact structure. Integrating the ionic wind generator with heat dissipation fins can effectively reduce the size of LED devices, but research in this area is still insufficient. In this study, an integrated ionic wind heat sink is designed for cooling LEDs. The multi-physical characteristics of discharge, flow, and heat transfer are numerically studied. The geometric parameters’ impact degree and mechanism on the multi-physical characteristics are analyzed. The performance optimization of the integrated heat sink is realized and verified. The fin length, flow channel center angle, and relative position of the fin have a large influence on the average velocity of ionic wind. The relative position of the wire electrode determines the electric field strength distribution, and it has the greatest influence on the ionic wind performance. The emitting electrode being placed at the inlet edge of the collecting electrode produces a high ionic wind flow rate. The integrated ionic wind heat sink designed in this study exhibits an outstanding cooling performance and temperature uniformity. This device can cool down the surface of a heat source with a power of 200 W to below 91 °C and make the average heat transfer coefficient reach 18.6 W/(m2·K). This study proposes a valuable method to optimize the integrated ionic wind heat sink for cooling high-power electronic devices.

Application of multi-stage ionic wind technology in glass curtain walls for enhanced thermal insulation performance

Glass curtain walls are widely used in architecture due to their aesthetic appeal and brightness. However, their thermal insulation performance is relatively poor, with natural convection within the cavity contributing significantly to overall heat transfer. To enhance the thermal insulation of double glazing curtain walls and reduce building energy consumption, we propose installing a multi-stage ionic wind generator on the curtain wall to weaken natural convection using ionic wind.In this paper, we introduce an ionic wind generator based on a wire-plate electrode configuration arranged in a plane, demonstrating that it follows the same discharge laws as electrodes arranged in space. An experimental platform was established to investigate the effect of multi-stage ionic wind on reducing natural convection within the cavity. The results indicate that ionic wind interference effectively weakens natural convection, thereby improving the thermal insulation of the glass curtain wall. Specifically, when voltages of 10 kV, 15 kV, and 20 kV are applied, the overall heat transfer coefficient of the double glazing cavity decreases by 5.56 %, 10.35 %, and 14.39 %, respectively. Numerical simulations visually record the process of weakening natural convection and provide electric field data for ionic wind. Additionally, we evaluated the Coefficient of Performance (COP) of the experimental cavity, which reached a maximum of 2.4 in our experiments. Future research can focus on optimizing energy efficiency. This study innovatively explores the feasibility of improving the thermal insulation of glass curtain walls using ionic wind, contributing to reducing building operational energy consumption and mitigating global warming.

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

Ionic wind generated by atmospheric pressure discharge can be used for propulsion, heat dissipation, food drying, which shows the unique advantages of no mechanical parts and fast response. However, the wind speed and the energy efficiency of ionic wind generator are very low, which limit its application. In this paper, an ionic wind generator, constructed with needle-net electrode structure and powered by high-voltage positive dielectric current (DC) power supply, is built for cooling of a metal oxide semiconductor field effect transistor (MOSFET). The energy efficiency and wind speed of the ionic wind generator are optimized by adjusting the electrode structure and applied voltage amplitude. The results show that when the discharge spacing is fixed at 10 mm and the optimal needle spacing is 17.5 mm with 6 needles at 14 kV, the ionic wind velocity can reach a maximum value 3.20 m s−1 and the energy efficiency is 1.90%. Under optimal experimental conditions, the heat dissipation performance of MOSFET is significantly enhanced compared to using only a heat sink. With cooling by the ionic wind generator, the MOSFET junction temperature can be lowered by about 29 °C after 240 s operation.

Numerical Simulations of Ionic Wind Induced by Positive DC-Corona Discharges

This paper analyzes ionic wind production and propulsive force in various electrode configurations under atmospheric conditions. By considering the aerodynamic forces in addition to previously considered electric ones, new predictions for steady-state forces and ionic wind flow velocity are successfully compared with experimental measurements, providing convincing quantitative evidence of the predictive capabilities of drift-diffusion modeling associated with one-way Coulomb forcing of Navier–Stokes equations for ionic wind generation. Furthermore, various electrode configurations are analyzed, some of them streamlined, reducing wakes downstream collectors on the one hand and providing additional thrust on the other. The quantification of these additional thrusts is analyzed, physically discussed, and explored in various configurations.

Ionic wind and ozone generation in a single magnetic fluid dielectric barrier discharge plasma actuator with different electrode configurations

Plasma actuators are compact wind power generators without mechanical power mechanisms. Plasma actuators have been investigated and developed. In a previous study of the authors, a single dielectric barrier discharge (DBD) plasma actuator using magnetic fluid (MF), termed “MF-DBD plasma actuator,” was proposed for application to fanless air purification devices that can collect low-resistive particulate matter, such as diesel particulate, by electrostatic force without re-entrainment. The fundamental characteristics of the MF-DBD plasma actuator, such as ionic wind, temperature distribution, and ozone and ion concentrations, were investigated in the previous study. The advantage of an MF-DBD plasma actuator is that the position and shape of the MF electrode can be controlled using a magnetic field. In view of this advantage, in this study, ionic wind and ozone generation in a single MF-DBD plasma actuator with different electrode configurations is investigated for the future development of MF-DBD plasma actuators and their application in fanless air purification. In these experiments, the width of the insulated electrode and the distance between the exposed and insulated electrodes are varied. As a result, in the case of a constant applied voltage, the ionic wind velocity and ozone concentration depend only on the overlap between the magnetic fluid and the insulated electrode, and these values increase as the overlap increases. It is clarified that a large overlap between the MF and insulated electrodes can generate an efficient ionic wind in terms of wind velocity and energy consumption.

Experimental and numerical study on transportation performance of ionic wind generator with distributed auxiliary heat source

Ionic wind technology can be used to achieve directional airflow transportation and local heat and mass transfer enhancement, which are suitable in the field of food drying. Ionic wind can be coupled with medium- and low-temperature heat sources to achieve collaborative heat and mass transfer while satisfying the requirements of efficient drying and maintaining food quality. However, the distributed heat source introduces ambient temperature gradients. Notably, different ambient temperature gradients of the generator exert obvious effects on the local molecular number as well as particle energy; this can affect the gas transportation performance of the generator, which has not been clarified thus far. Herein, the gas transportation performance of a wire-mesh ionic wind generator operating at different heat-source temperatures is experimentally and numerically investigated. The experimental results show that ionic wind generators operating at normal atmospheric temperature are more beneficial to obtaining a high mass flow rate and local velocity of ionic wind. Additionally, continuously increasing the heat source temperature can improve the transportation performance of ionic wind generators. In the simulation, an electrohydrodynamic (EHD) force is introduced to indicate ionic wind strength. The simulated EHD force reaches the highest value without a temperature difference between the two electrodes. The variation trend of the simulation results is consistent with that of the experimental results. The simulation results emphasize the combined effects of particle energy and air molecule number on ionic wind strength, which can explain the phenomena observed in the experiments. This study thus provides a theoretical guideline for the design and combined application of ionic wind generators and distributed auxiliary heat sources.

Study on the Influence of Central Hole Diameter in a Wire Mesh Electrode on Ionic Wind Characteristics.

Ionic wind, which is generated by a corona discharge, is a promising field that offers significant advantages by directly converting electrical energy into kinetic energy. Because of the electrical characteristics of ionic wind, most studies aiming to improve the performance of ionic wind generators have focused on modifying the geometry of electrode configurations. A mesh-type electrode is one of the electrodes used as a collecting electrode in an ionic wind generator. Using a mesh electrode results in decreased momentum of the ionic wind and increased pressure drop due to frictional loss of the flow. In this study, to minimize the reduction in momentum, a mesh electrode with a central hole was proposed and investigated. Experiments were conducted with the configuration of a needle and mesh with the central hole. These experiments analyzed the effect of the central hole diameter and the distance between the needle and the mesh electrodes on the electrical and physical characteristics of the ionic wind. The addition of the central hole led to a higher average velocity and lower current, thus resulting in increased energy conversion efficiency. The presented configuration offers a simple geometry without electrical and physical interference from complex configurations, and it is considered to have the potential to improve energy conversion efficiency and optimize ionic wind flow.

Electrohydrodynamic devices for ionic wind generation and airborne positive‐strand RNA viruses inactivation by nonthermal atmospheric plasma

AbstractAdaptable technologies capable of reducing contaminants in enclosed spaces are needed. The SARS‐CoV‐2 pandemic has highlighted the vulnerability of current systems forcing the adoption of extreme measures, causing a significant socioeconomic impact. Electrohydrodynamic devices are proposed as a competitive solution that allows obtaining a high degree of viral inactivation with a very low generation of chemical compounds and low power consumption, together with the production of an airflow, which makes its implementation in real environments easy. In this study, airborne positive‐strand RNA viruses are treated with nonthermal atmospheric plasma, achieving >3.4‐logR for HCoV‐229E and Bacteriophage‐MS2 and >2.4‐log SARS‐CoV‐2 at 4W, in a single pass, at O3 and NO2 concentrations ≤0.70 ppm. Electrical, fluid‐dynamic, and chemical characterization provides the design rules.

Ionic wind generation through coplanar discharge: A plasma actuator without exposed electrodes

This study demonstrates the successful induction of a unidirectional ionic wind by adding an embedded electrode in a coplanar discharge, thus breaking the generation of a symmetrical electric field. The strategy for the ionic wind generation is based on separating the ionization process and the charged-particle acceleration process. Conventional plasma actuators used to induce an ionic wind typically incorporate exposed electrodes that pose a risk of unexpected airflow disturbance and reduce durability due to oxidation. However, the coplanar discharge-based, exposed-electrodeless plasma actuator developed in this study overcomes these issues. The coplanar discharge generates a diffused and uniform surface discharge, a desirable attribute for plasma actuators. The ionic wind velocity generated by this coplanar discharge plasma actuator is comparable to that generated by conventional plasma actuators when applying a square-waveform bias voltage to the additional electrode. Furthermore, this study emphasizes the significance of the phase difference between the repetitive pulses for generating coplanar discharge and the square-waveform voltage for accelerating the charged particles.

Issledovanie vliyaniya skorosti nabegayushchego potoka na techenie, indutsiruemoe dielektricheskim bar'ernym razryadom

Plasma actuators based on a dielectric barrier discharge (DBD) are considered as a promising method оf flow control. Their main advantage is the possibility of flow acceleration by the ion wind without using movable elements. The generation of the ion wind by DBD in a settling gas has been studied quite comprehensively. At the same time, almost all aerodynamic applications of this method of flow control presume the presence of an external flow. However, the emergence of a bulk force in DBD in such conditions has not been investigated in detail. This study is devoted to detailed analysis of this effect. We have investigated the influence of DBD on the velocity distribution near electrodes using the PIV method and have calculated the bulk force generated by the ion wind. The results of this study demonstrate a substantial effect of the incoming flow velocity on the ion wind generation.

Improve the secondary structure of the series ionic wind generator to regulate the flow distribution and its application in electronics cooling

The substantial amount of heat released by power electronic devices as they go toward increasing frequency and higher integration offers significant challenges for electronics cooling. Dual-stage ionic wind generators with a V-shaped ‘needles-to-rings' design are presented. To achieve higher cooling efficiency, the ionic wind flow distribution was managed by improving the structure of the sub-unit. The calculation was performed using a two-dimensional model. By coupling an electric field, flow field, the development of ionic wind flow was simulated. Experiments were carried out in order to assess the EHD properties of the designed ionic wind generators, as well as the cooling impact on a high-power LED chip. The findings show that the convergent outlet structure has several defects, resulting in large momentum loss. The dual grounded rings in the sub-unit may spread the ionic wind more efficiently, providing charged particles with a stronger forward driving force and more possibilities to produce ionic wind. The ionic wind has a wide distribution range, a maximum wind velocity of 2.46 m/s, and provides improved cooling for the LED chip.

Comparison of Initiation and Temporal Evolution of Positive and Negative Ionic Wind Under Needle-to-Plate Electrode

Considerable research efforts have been devoted to the generation, characterization, and optimization of ionic wind produced by corona discharge. The current article tries to explain the mechanism that causes the different behaviors observed in negative and positive dc corona ionic wind. The steady-state and the transient state ionic wind produced by both polarities are studied through particle image velocimetry (PIV) technology. The results show that at transient state, a series of mushroom-like jets are produced in negative corona discharge ionic wind due to the effect of Trichel pulse. These jets merge with each other and combine momentum to form the wide structure at steady state. In comparison, the positive corona discharge current has no pulse, and the ionic wind has only one “I-shape” wave head during the initiation process. The dynamics of the jets is studied in detail. The formation of the jet series in negative corona, or single jet in the case of positive corona, is believed to play a key role in the generation of ionic wind.

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

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 electrode structure on the discharge characteristics and the converting efficiency from electric energy to kinetic energy 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 change the spatial electric field distribution, increase the field intensity of the discharge gap, and promote the particle collision. 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.

Local hotspot thermal management improved by ionic wind generator coupled with porous materials

Ionic wind is induced by corona discharge caused by extremely inhomogeneous electric field between two electrodes. Due to its compact size, energy saving, flexible design, and easy integration, ionic wind technique exhibits great potential to improve hotspot cooling, especially for compact electronic devices. However, the heat removal capability towards high power density is relatively low due to the limited heat transfer area and low air thermal conductivity. The principle and designs are still lacking for local hotspot cooling. Here, an ionic wind generator with a novel architecture coupled with porous medium is conceived to enhance cooling performance. It is demonstrated that when a porous medium block is coupled, heat transfer can be significantly boosted due to the modified heat and mass transfer in the porous block. It is also found that electrode configuration significantly influences the device performance. There is a trade-off between heat transfer area and airflow impediment in the device. The geometry and property parameters of the porous block are critical for the cooling performance, which is attributed to the modified flow field by changing porous structure. Based on this principle, another ionic wind generator improved by a coupled heat sink with porous fins is proposed, whose performance can be further enhanced by optimizing its design parameters. The optimized heat sink structure can maintain the max temperature of the cooling surface below 83.2 °C at a heat flux of 90 kW/m2. This study provides a promising way for air-side thermal management of hotspot. The findings are helpful for understanding EHD-induced airflow heat transfer in porous medium and shed new light on designing ionic wind generators with better performance.

Enhancement of thrust force of an atmospheric pressure positive corona discharge by DC superimposed AC high voltage

The ability of corona discharge as an electrohydrodynamic propulsion system has been considered by many physicists and aerospace researchers. The results show that the most important factor in increasing the thrust force and thrust effectiveness is increasing the momentum transmission frequency in other words reduction of ion mobility that leads to a reduction of the average velocity. By configuring the wire-cylinder in atmospheric conditions, in an experimental study, using a new strategy in generating corona discharge, and without changing the system configuration, the thrust force is increased by increased of exciting species and reducing the ion mobility. DC superimposed AC (AC-DC) voltage source was utilized to achieve higher thrust force efficiency. Results show that the thrust force generated by the AC-DC source is increased by 4–2 times, with the applied voltage range of 10–20 kV compared to the DC source, respectively; while the thrust effectiveness has also been increased. A theory is introduced to calculate the thrust force due to ionic wind generation in the corona discharge regime. Accordingly, a relation is obtained for calculating thrust force and ion mobility using the average vertical ionic wind velocity on the side of the grounded electrode to support experimental results.

Electrohydrodynamic and heat transfer characteristics of a planar ionic wind generator with flat electrodes

• Two corona discharges with different polarities are produced simultaneously. • The minimum discharge gap to maintain a stable corona discharge is determined. • The intensity and direction of the generated ionic wind is revealed. • The relationship between the heat transfer enhancement ratio and power consumption is established. In this study, a planar ionic wind generator with two flat electrodes was investigated numerically and experimentally to reveal its electrohydrodynamic and heat transfer characteristics. The multi-physical characteristics, including the discharge process, movement of electrons, positive ions, and negative ions, as well as the formation of ionic wind and its flow characteristics were simulated numerically. It was found that two corona discharges with different polarities were produced simultaneously when a high voltage was applied between the emitting and the ground electrodes. The intensity and direction of ionic wind produced by planar ionic wind generator was revealed. The effects of discharge gap, flat electrode thickness, and discharge polarity on the heat transfer characteristics and power consumption of the planar ionic wind generator were also investigated experimentally. The minimum discharge gap to maintain a stable corona discharge is determined. A better heat dissipation capacity of the planar ionic wind generator can be obtained with a larger electrode gap, and the optimized ionic wind generator can reduce the surface temperature of a 2.05 W powered heat source by more than 46 °C compared with natural cooling. The maximum heat transfer coefficient is 35 W∙m −2 ∙K −1 . This study can provide a theoretical guidance for the application of planar ionic wind generators to highly compact electronic devices.

Improve the Secondary Structure of the Series Ionic Wind Generator to Regulate the Flow Distribution and its Application in Electronics Cooling

Improve the Secondary Structure of the Series Ionic Wind Generator to Regulate the Flow Distribution and its Application in Electronics Cooling

A Magnetically Actuated Plasma Device for Ionic Wind Generation

A Magnetically Actuated Plasma Device for Ionic Wind Generation

The Optimization of Needle-Net Ionic Wind Generator Electrode Structure and Heat Dissipation Performance

The Optimization of Needle-Net Ionic Wind Generator Electrode Structure and Heat Dissipation Performance