极性液体电介质旋转椭球极化模型
来源期刊：中南大学学报(自然科学版)2001年第3期
论文作者：蒋礼
文章页码：267 - 269
关键词：电介质;极化强度;旋转椭球;有效极化;电场强度
Key words：dielectric; polarization intensity; rotate ellipsoid; effective intensity; polarizing electric field
摘 要：在油与水的混合电解质中,水比油的极性强,为极性液体电解质.当油中含有少量水时,水以悬浮胶粒状、粒径为1×10-4cm的小水球形式存在于油中.当外电场作用时,油中小水球被极化,它的形状发生改变,在电场方向被拉长而成为椭球,束缚电荷分布在椭球表面.作者对极性液体电介质进行了研究,根据水球被拉长的实际情况和椭球的性质,建立了旋转椭球极化模型,在该模型基础上,把束缚点电荷的电场折合到椭球中心的电场,推导出椭球中心有效极化电场的场强公式,给出了旋转椭球表面束缚电荷在椭球中心的极化电场强度E1″.研究结果表明:极化电场强度与旋转椭球的长、短半轴之比的平方有关,呈非线性,比圆球模型的电场强度P/(3ε0)复杂;由旋转椭球极化模型得到的结果用于研究混合电介质的“气桥”或“水桥”击穿现象,更能反映其物理本质.
Abstract: In the dielectric of oil mixed with water, the polarization of water is more powerful than oil. When there is little water in oil, water appears in colloidal suspension state (about 1×10-4cm, small water balls) . While external electric field acts on the balls, they are polarized, their shape is changed, pulled long, and becomes ellipsoid. The bound charges are distributed on the surface of the ellipsoid. In this paper the polarity liquid dielectric was studied. According to the practical case and property of ellipse, a polarizing model of polarity liquid dielectric rotate ellipsoid was set up. On the basis of the model, the electric field E1″of the bound charges was converted into electric field of the ellipsoid center, the formula of the effective polarizing electric field intensity at the rotate ellipsoid center was deduced, the polarizing electric field of the rotate ellipsoid bound charges at ellipsoid center was given. It is related to the square rate of long and short half axle, nonlinear, and is more complicated than the field intensity P/(3ε0)of the ball model. The research shows that the polarizing model of polarity liquid dielectric rotate ellipsoid is of more physics essence, when it was applied to studying the breakdown of the “gas bridge” and “water bridge” in the mixed dielectric.
