Simulation and Experimental Study on the Characteristics of Metal and Dielectric Spheres in a Pulsed Dielectric Barrier Discharge

In this article, a 2-D fluid simulation model of a coaxial cylindrical DBD reactor filled with single solid spheres of two different materials is developed for plasma-assisted milling discharge studies. In this article, the evolution, quenching process, and comparison of the discharge characteristics, including its current, electron density distribution, and electric field distribution, of stainless steel and SiO2 spheres discharged at atmospheric pressure DBD were investigated separately, and the discharge images were captured by using an ICCD camera to further validate the results predicted by experimentally established models. The following conclusions were obtained from the study. First, in terms of current, the initial discharge moment of SiO2 spheres is slightly later than that of stainless steel-filled spheres. During the rising edge of pulse voltage, there was only one DBD current peak in stainless steel-filled spheres, while there were two current peaks in SiO2-filled spheres, and the first current peak was smaller than the second, indicating that the second discharge was stronger than the first. Second, electron density distribution and ICCD images show that the discharge is mainly concentrated in the volume discharge at the top of the spheres when stainless steel-filled spheres are present. Comparatively, SiO2 spheres first experience a period of volume discharge, followed by a more diffuse discharge around the spheres, especially in the entire region between the top of the spheres and the dielectric layer. Overall, the SiO2 spheres show a more intense discharge compared to the stainless steel spheres.