Effect of dielectric temperature on Ar atmospheric pressure nonequilibrium plasma jet with different dielectric materials

Summary form only given. In this work, effect of dielectric temperature on atmospheric pressure nonequilibrium plasma jets (APNPJs) with different dielectric materials has been investigated
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. In our experiments, a single-electrode plasma generation equipped with an AC power supply is applied. Two materials, 95% alumina ceramic and quartz are adopted as dielectric tube. To distinguish the APNPJ status from the argon flow rate, the three modes, laminar, transition and turbulent, are separated.It is found that, with the dielectric wall heated, the APNPJ len gth and volume are enhanced over a large range of flow rates with both ceramic and quartz tube. Contrast with the situation of quartz tube, the transition regions has a significant `bulge' in ceramic tube with heated wall. This result indicates that di fferent factors contribute to the expansion of the transition re gion. The increase in the radial and axial velocities is the mai n cause of the expansion of the transition region to the low-ve locity region. The expansion to the high-velocity region is do minantly induced by a change in the viscosity. For the case of high temperature in quartz tube, the peak length of plasma pl ume has even greater enhancement under different applied vo ltages. The maximum values of jet length with 7 kV applied voltage are 5.15 cm in quartz tube and 4.50 cm in ceramic tu be, respectively. For both ceramic and quartz tube, obvious di stinction of longest length versus applied voltage is disclosed between two different dielectric temperatures. In room tempe rature, the trend of longest length versus voltage is upward, b ut it shows an entirely opposite tendency in high temperature. It is believed that the interaction between the dielectrics and plasmas is the dominant reason.