目的 研究 DOD 式压电喷墨打印系统液滴形成过程。 方法 简化压电式喷墨打印头的几何模型， 建立基于流体体积法的流体仿真模拟系统， 模拟给定压力条件下液滴生成的全过程， 并以此进行数值实验来评估油墨的表面张力和黏度对喷墨中液滴形成形态的影响。 结果 给出不同瞬间液滴的形态， 得出适合于给定条件的最优参数组合。 引入流体力学中的无量纲常数Z， 评价表面张力和油墨黏度在耦合作用下液滴的成形状态。 确定表面张力约为 40 mN/m、黏度约为 10 Pa· s、无量纲常数Z为4.56的油墨能够得到理想的单液滴喷射形态。 结论 将仿真的结果应用到实验中， 对比分析可知吻合较好，证明了数值模拟的可靠性。

Objective To investigate the formation processes of droplet in a piezoelectric system. Methods The system simulated the droplet formation and ejection of a piezoelectric inkjet printing device based on VOF method under the condition of a given pressure. The effects of ink physical properties (including surface tension and viscosity) on the ejection behavior of droplet were presented. Results The typical moment of the formation process was given. The proper parameters to get ideal monodisperse droplet were determined. The proper surface tension was 40 mN/m and the viscosity was 10 Pa· s, which meant that Z was 4.86. Conclusion The conditions to get the ideal droplet form were validated by the experimental observation, which proved that the simulation was reliable.