Effect of transverse airflow on the deflection of negative corona discharge on the Trichel pulse mode at atmospheric pressure

Abstract

Negative corona discharge can deflect in transverse airflow in pin-to-plane electrodes at atmospheric pressure. In this paper, we investigate the mechanism of Trichel pulse discharge deflection in transverse airflow and give a further understanding of the dynamic process of the deflection through experiments and simulations. In experiments, we quantitatively record the deflection angle by processing the discharge images, and they show that a larger airflow speed will lead to a larger deflection angle. In simulations, the discharge deflection angle is calculated through a 2D fluid model. Besides, the periodic fluctuation of the deflection angle with Trichel pulses is revealed, and this phenomenon can be explained by the alternative dominant effect of airflow or ionization on the net production of positive ions in the vicinity of the tip. When the effect of airflow is dominant, more positive ions will generate away from the center of the tip, which will lead to an increase in the deflection angle. On the other hand, when the effect of ionization prevails, more positive ions will generate near the center because the electric field here is stronger, and the deflection angle will decrease. In addition, if these two effects balance, the deflection angle will reach its maximum or minimum value.

DC-driven positive streamer coronas in airflow

“…Qualitatively, this behavior has been experimentally observed by Vogel et al [6]. For negative Trichel corona discharges, Guo et al [7] found that the filamentary discharge angle with respect to the vertical increases with wind speed (tilting towards the wind direction) and decreases with applied voltage (aligning with the main vertical electric field), using both experiments and numerical models.…”

“…To address this question, the methods described in section 2.2 are used specifically to investigate the relationship between the streamer burst orientation (relative to the wind) and the pulsation period and peak current magnitude. The orientation of the streamer burst is quantified by taking the radially averaged intensity of each image, using polar coordinates and within a region of 0.5 mm about 5 mm away from the needle tip, as shown in Figure 4 and as described by Guo et al [7]. Each image is then reduced to an angle-intensity profile which is paired to the corresponding inter-pulse period and peak current.…”

Numerical approaches in simulating Trichel pulse characteristics in point-plane configuration

“…The issue of emission of ultrasonic waves was addressed in [16] considering the linearized form of Navier-Stokes' (NS) equations. Finally, the effect of ionic wind and transverse flows were discussed in [17][18][19], respectively.…”

“…In some scenarios, bulk motion is not negligible and must be considered. Instead of solving the NS equations, Guo et al [19] considered the convective flux with a constant air velocity, to investigate the effect of the transverse airflow. Assuming the ionization and attachment coefficients are influenced by the air humidity and pressure, as it was discussed earlier in [27], the heating, humidity and pressure effects were discussed in [54,55].…”

Research on characteristics of decoupled electroaerodynamic thruster with auxiliary electrode

“…When the electrode distance was increased to 5 and 7 mm, the divergence angle decreased to 42 and 25 • , respectively. The calculation method is from Reference[17]. In addition, when the auxiliary electrode radius was increased to D = 5.5 mm, for L 1 = 1 mm, the discharge intensity of the ionization region was significantly enhanced, and arc discharge channels can be observed in the acceleration region when the negative DC voltage is approximately −1.5 kV.…”