为研究电场作用下表面张力对液滴运动特征的影响,基于润滑理论和漏介电质模型,在考虑受电场影响的表面张力变化的基础上,建立了电场作用下液滴铺展的演化模型,采用PEDCOL程序模拟了在不同底部电势影响下导电液滴的运动特征。研究表明:两极板间的液滴铺展过程不仅与电势类型有关,还与因电场作用下改变的表面张力有关;表面张力比例系数对液滴运动过程的影响总趋势大体相同,但最大液膜厚度和铺展半径的变化速率明显不同。施加均匀电势和线性电势时,并不改变液滴铺展的抛物线外形,随比例系数增大,液滴铺展加快;施加非线性电势时,可控制液滴的破裂过程;液滴铺展过程中,受表面张力变化影响最大的是线性电势,最小的为指数电势。
To analyze the effect of surface tension on droplet dynamics in the presence of electric field,an evolution model considering the surface tension variation induced by electric field was established based on leaky dielectric model and the lubrication theory. The PEDCOL code was utilized to simulate the dynamic characteristics of a conductive droplet in the presence of diverse electric fields. Results show that the droplet movement between two electrode plates is not only related to the potential type,but also influenced by the variation of the surface tension induced by electric field. The influence of the proportion coefficient of surface tension on the droplet movement process is approximately same while the maximum thickness of liquid film and spreading radius variation rates are obviously different. Exerting uniform and linear electric potential does not alter the parabolic shape of spreading droplet. With the increase of the proportion coefficient,the droplet spreading is accelerated. Rupture process of a droplet can be controlled by applying nonlinear electric potential. The greatest impact of the variation of surface tension on the process of a droplet spreading is linear potential,and the least impact is exponential potential.