Investigation of spherical and concentric mechanism of compound droplets

Matter and Radiation at Extremes - Tập 1 - Trang 213-223 - 2016
Meifang Liu1, Lin Su1, Jie Li1, Sufen Chen1, Yiyang Liu1, Jing Li1, Bo Li1, Yongping Chen2,3, Zhanwen Zhang1
1Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
2School of Energy and Power Engineering, Yangzhou University, Yangzhou, Jiangsu, 225127, China
3Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, Jiangsu, 210096, China

Tóm tắt

Polymer shells with high sphericity and uniform wall thickness are always needed in the inertial confined fusion (ICF) experiments. Driven by the need to control the shape of water-in-oil (W1/O) compound droplets, the effects of the density matching level, the interfacial tension and the rotation speed of the continuing fluid field on the sphericity and wall thickness uniformity of the resulting polymer shells were investigated and the spherical and concentric mechanisms were also discussed. The centering of W1/O compound droplets, the location and movement of W1/O compound droplets in the external phase (W2) were significantly affected by the density matching level of the key stage and the rotation speed of the continuing fluid field. Therefore, by optimizing the density matching level and rotation speed, the batch yield of polystyrene (PS) shells with high sphericity and uniform wall thickness increased. Moreover, the sphericity also increased by raising the oil/water (O/W2) interfacial tension, which drove a droplet to be spherical. The experimental results show that the spherical driving force is from the interfacial tension affected by the two relative phases, while the concentric driving force, as a resultant force, is not only affected by the three phases, but also by the continuing fluid field. The understanding of spherical and concentric mechanism can provide some guidance for preparing polymer shells with high sphericity and uniform wall thickness.

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