正弦削波电压调控大气压氦气非平滑表面介质阻挡放电均匀性的仿真研究

Numerical study on uniformity of atmospheric helium gas dielectric barrier discharge on non-smooth surface regulated by sinusoidal clipping voltage

在大气压介质阻挡放电的实际应用中,等离子体通常作用于非平滑表面.其表面形貌导致的电场畸变和表面电荷分布不均匀,会对放电的均匀稳定产生不利影响.建立了下介质板为波浪状的大气压氦气介质阻挡放电仿真模型,并采用正弦削波电压对放电均匀性进行调控.结果表明:相比于未削波情况下,放电均匀性提高,介质阻挡放电从柱状放电模式转换为准均匀放电模式.这可以归因于气隙电压降低而产生的不完全放电消散;随后的电子回流过程使残余空间电子与表面电荷中和,限制了表面电荷积累.随着削波比例增加,表面电荷分布更为均匀,进而导致电场分布在径向上波动减弱.此外,在一定削波范围内放电效率也有所提高.本研究揭示了削波电压对非平滑表面介质阻挡放电的影响机理,为介质阻挡放电均匀性调控提供了新的思路.

In practical applications of dielectric barrier discharges under atmospheric pressure,plasma usually acts on non-smooth surfaces.The electric field distortion and uneven surface charge distribution caused by its surface morphology will create an adverse effect on the uniformity and stability of the discharge.In this paper,we establish a simulation model of atmospheric pressure helium dielectric barrier discharge on a wavy lower dielectric plate,and use a sinusoidal clipping voltage to regulate the discharge uniformity.The results show that the discharge uniformity is improved compared with the unclipped case,and the discharge mode is changed from columnar mode to quasi-uniform mode.This can be attributed to the incomplete discharge dissipation caused by the reduction of air gap voltage;the subsequent electron backflow process neutralizes the the residual space electrons with the surface charge,which limits the accumulation of surface charges.With the increase of clipping ratio,the surface charge distribution becomes more uniform,and the radial fluctuation of electric field distribution weakens.In addition,the discharge efficiency is improved in a certain clipping range.This study reveals the mechanism of clipping voltage influence on non-smooth surface discharge,and provides a new idea for regulating the uniformity of dielectric barrier discharge.