Experimental Investigation of Two-Phase Mixture Discharges Under DC Voltage From Effects of Macroparticle Sizes

There has been a significant interest in many technical applications and natural phenomena concerning two-phase mixture discharges (TPMDs). Few studies have focused on the influences of different macroparticles on TPMDs. The dielectric constant is usually considered to be the only factor affecting the discharges, but in this paper, 21 kinds of different dielectric materials were used to investigate the effects on TPMDs. By the experimental results, this paper reveals the effects of macroparticle sizes, and the dielectric constant has little influence. When the diameter of TPMs is less than about 0.01 mm, the percentage of the selection of TPMs is always smaller than 50%, the discharge path selects the air but TPM, and the breakdown voltage is higher than that in air. However, when the diameter is greater than about 0.1 mm, the conclusion is opposite. When the diameter is in the range of 0.01-0.1 mm, the TPMDs have a polarity effect. The dipole-enhanced approximation model is applied to explain the experimental phenomena. It is very important in TPMDs that the macroparticle dielectric constant, the saturation charge, and the adsorption/desorption process on the material, except the effects of TPMDs, are highly correlated with the macroparticle sizes.