Abstract: In order to study boiling transfer enhancement mechanism，with water as working medium，the boiling bubble behavior under the influence of electric field was investigated. High-speed video camera was used to observe the growth process of bubble produced by direct heating with different heat flow densities and electric field intensities and the shape of escaping bubble，cycle and ratio of length to diameter of bubble were analyzed. The experimental result and related qualitative analysis were used to explain EHD enhancement of boiling heat transfer mechanism. Electric field had a significant effect on the behavior of bubble. The bubble was stretched along the direction of electric field intensity. The ratio of length to diameter of bubble increased with increasing heat flow density and electric field intensity. The cycle of bubble decreased with increasing heat flow density and electric field intensity. Synergy of electric field and thermal field synergy helped to reduce bubble residence time and consequently the thermal resistance between heat source and fluid，indicating the effect of boiling heat transfer enhancement.

Key words: electric field, shape, boiling bubble, experimental study

摘要： 为了进一步探讨电场对沸腾传热强化机理，以水为实验工质，实验研究了电场作用下沸腾单个气泡的行为特性。通过直接加热法产生单个沸腾气泡，并利用高速摄像机拍摄观察了不同热流密度和电场强度组合工况下气泡的生长过程，并对该过程中对电场作用下气泡的脱离形态、周期和长径比等行为特性变化进行了相关定性分析，根据实验结果和相关定性分析，进一步合理阐释了电水动力学强化沸腾传热机理。结果表明：外加电场工况后，电场对沸腾气泡的脱离形态有显著的影响，气泡沿场强方向拉伸变形且场强越大，拉伸变形越明显；气泡的脱离长径比随着电场强度和热流密度的增大而变大；气泡的脱离周期随着电场强度和热流密度的增大而减小。这表明电场和热场协同作用有助于减小气泡的停留时间来减小热源于流体之间的热阻，进一步说明电场和热场对沸腾强化传热有一定的影响。

关键词: 电场, 形态, 沸腾气泡, 实验研究