超声波作用下油中水滴的运动与变形特性

采用显微高速摄像系统结合图像处理技术对超声波作用下油中水滴的运动与变形行为进行了拍摄和分析。结果表明，超声波作用显著影响油中水滴的运动轨迹、速率以及振荡幅度和频率，水滴作类正弦振荡运动，粒径为200～400 μm的水滴振荡运动最为剧烈；随超声波声强的增加，水滴振幅先增加后减小，在本实验体系下的临界声强为4.89 W/cm²。超声波作用下，油-水界面被周期性拉伸和压缩，水滴呈周期性变形，其变化周期和振荡周期一致。随水滴粒径的增大，其最大变形度先减小后增大；随油相黏度、油-水界面张力的减小以及声强的增大，水滴最大变形度增加。

Movement and Deformation Characteristics of Water Droplets in Oil Under Ultrasonication

By using microscopic high-speed camera system combined with image processing technology, the movement and deformation characteristics of water droplets under ultrasonication were captured and analyzed. The results indicated that ultrasonication had an obvious effect on the movement trajectory, the speed and the oscillation amplitude and frequency of water droplets. The water droplet did similar sine oscillation movement. Especially, the water droplets with the diameter between 200 and 400 μm did the most severe oscillation movement. With the increase of ultrasonic intensity, the oscillation amplitude of water droplets increased and then decreased. The critical value of ultrasonic intensity was 4-89 W/cm². Under ultrasonication, the oil-water interface was periodically stretched and compressed, which led to the water droplet’s periodic deformation, and the deformation period was just the same as the oscillation period. With the increase of droplet size, the maximum deformation degree of water droplet decreased at first and then increased. With the decreases of oil viscosity and interfacial tension and with the increase of ultrasonic intensity, the maximum deformation degree of water droplet increased.