汽泡在电场作用下的变形

BUBBLE DEFORMATION IN AN ELECTRIC FIELD

为探明外加电场对汽泡形状的影响规律,本文采用人工注射汽泡的方式,对均匀电场作用下单个汽泡的形状进行了可视化试验研究,计算了汽-液两相系统中的电场分布及汽泡所受的电应力。结果表明:电场作用下汽泡表面所受电应力分布的不均匀性导致汽泡沿与电场相平行的方向拉长,变成扁长椭球形。随着场强的增加,汽泡变形量加剧,汽泡与壁面的接触角逐渐变大。此外,讨论了汽泡变形对电场强化沸腾换热的影响。

In order to clarify the effect of an electric field on the bubble shape, the visualized experiments are carried out on a single bubble formed by manually injecting in a uniform electric field, and the electric field distribution in the bubble-liquid two-phase system and the electric stress acting on bubble are calculated. The results indicate that the electric stress on the bubble surface is nonuniform, which results in the bubble being elongated in the direction of electric field and deformed into a prolate spheroid. The rate of bubble deformation and the contact angle increase as the electric field strength increases. In addition, the effect of bubble deformation on EHD-enhanced boiling heat transfer is discussed.