非零迎流角半球缺群无阀泵流场及流量特性

理论研究了以半球缺群作为无移动部件阀的无阀压电泵的液体输送和混合搅拌功能,针对半球缺群迎流角的变化对该压电泵的泵送性能及混合搅拌效果的影响进行了仿真分析与试验验证。围绕迎流角θ在0°≤θ≤90°的变化,建立多组有限元模型,模拟了半球缺群迎流角变化引起的速度场、压强差、阻力系数及仿真流量的变化规律,并进行了试验验证。结果表明,0°≤θ≤45°时,仿真流量随θ的增加而增加;45°θ≤90°时,仿真流量随θ的增加而减小;θ≈45°时取得最大流量96.13mL/min。此外,研究显示旋涡的大小及强度具有与仿真流量相同的变化趋势。泵流量试验验证了仿真研究及其结果的正确性:在θ≈45°时,试验流量达到67.90mL/min;0°θ≤360°时,试验流量与仿真流量的变化趋势一致,并且θ在一个周期的变化中泵流量及旋涡强度出现2次正向最大值和2次反向最大值。本研究为优化无阀压电泵的泵送性能和混合功能奠定了基础。

Flowfield and flow rate properties of valve-less piezoelectric pump with flow-facing angle hemisphere-segment group

The fluid delivery and fluid mixing functions of a valve-less piezoelectric pump by taking a hemisphere-segment group as no-moving part valve were researched. The influences of flow-facing angle θ change on pumping and mixing performance of the valve-less piezoelectric pump were simulated and verified experimentally. For the flow-facing angle changes in the range of 0°≤θ≤90°, several kinds of finite element models were established and the change laws of velocity field, pressure difference, flow resistance coefficient and flow rate caused by different flow-facing angles of hemisphere-segment group were simulated. The results show that when 0°≤θ≤45°, the simulation flow rate increases with the increasing of θ; when 45°<θ≤90°, that decreases with the increasing of θ, and when θ≈45°, that reaches to the maximum value of 96.13 mL/min. Meanwhile, the change laws of vortex size and strength caused by the change of flow-facing angle are the same as the simulation flow rate. The experiments on pumping flow rate with pump prototype verify the simulation results, the experimental flow rate reaches to the maximum value of 67.90 mL/min at θ≈45° the change trends of experimental and simulation flow rates are the same at the range of 0°<θ≤360°. During the flow-facing angle changes in a cycle, the flow rate and vortex strength reach to their forward and reverse maximum values twice respectively. The research in this paper lays a foundation for pumping performance optimization and fluid mixing delivery.