电流体动力学对泄漏介电介质中液滴稳定性的影响
Influence of Electrohydrodynamic on Droplet Stability in Leaky Dielectric Media
AI总结：
研究介电液体液滴在均匀电场下的变形动力学及内部电流体动力流，通过阴影成像和三维拉格朗日粒子追踪等方法，明确了不同电场强度下硅油滴在蓖麻油中的行为状态及相关特性。
AI中文摘要：
本工作研究了介电液体液滴在均匀电场作用下的变形动力学。实验研究涉及两相配置，即硅油滴悬浮在蓖麻油中。利用阴影成像在一系列电场强度下研究了液滴的变形、伸长、振荡和旋转等动力学。同时，使用荧光示踪粒子和摇盒技术进行三维拉格朗日粒子追踪，以详细表征均匀电场作用下液滴内部的电流体动力流。对于蓖麻油介质中的硅油滴，最初会变形为扁球形。在足够高的电场强度下，液滴会经历电流体动力不稳定性，由于感应电转矩不平衡，其轴会与电场方向成一定角度排列。进一步增加场强时，液滴在进入瞬态稳定配置之前会表现出振荡变形。本研究根据液相的相对介电和流体特性，识别并表征了液滴行为的不同状态，从低电场下的初始变形到高场强下的振荡行为。
英文摘要：
This work examines the deformation dynamics of dielectric liquid droplet when exposed to a uniform electric field. The experimental investigation involves two-phase configurations, here as silicone oil droplets suspended in castor oil. The droplet dynamics including deformation, elongation, oscillation, and rotation are investigated over a range of electric field strengths using shadow-imaging. In parallel, fluorescent tracer particles were employed to perform threedimensional Lagrangian Particle Tracking (3D-LPT) using the Shake-The-Box (STB) technique, allowing for a detailed characterization of the internal electrohydrodynamic flow within the droplet subjected to a uniform electric field. For silicone oil droplets in castor oil medium (S/R > 1), the droplets initially deform into oblate shape. At sufficiently high electric field strengths, the droplet undergoes an Electrohydrodynamic instability, aligning their axis at an angle to the direction of electric field due to the imbalance in induce electric torque. Upon further increasing the field strength, the droplets display oscillatory deformation before settling into a transiently stable configuration. The current study identifies and characterizes the distinct regimes of droplet behaviour, from initial deformation at low electric fields to oscillatory behaviour at high field strengths depending upon the relative dielectric and fluid properties of the liquid phases.
