Abstract:

A model of through-hole capillary burst valve (CBV)is provided with the theory of contact line.The CBV is affected by the dynamic contact angle, expansion angle and advanced contact angle.The requirement for the model is confirmed by the experiment and numerical simulation.Based on the experimental data, a one-dimension model is presented to design the CBV where the flow is perpendicular to the coming flow channel.A new convergent through-hole CBV is designed.When the length of the coming flow channel is larger than 4mm, the CBV is not affected by the degree of the expansion angle of CBV.The experiment with deionized water shows that the CBV with 20 μm height still works well when the capillary number is as high as 4.0×10^-3.The CBV designed has the merit that it is easier to meet the requirement for manufacturing the expansion angle of the through-hole.

Key words:

毛细管被动阀, 通孔, 扩张角, 接触角

摘要：

根据接触线理论建立了通孔形毛细管被动阀的物理模型，分析了实际加工通孔时带来的扩张角对毛细管被动阀性能的影响，并推导出相应的成立条件。指出被动阀的有效性与液体对壁面的动态接触角、前进接触角和通孔的扩张角有关，实验结果验证了上述结论。根据实验结果，提出了简化的一维模型，用于通孔微阀的设计。通过数值模拟，得到一种新型的收缩形通孔微阀，当来流通道大于4 mm时，微阀有效性不受来流和通孔扩张角大小影响，降低了对通孔的加工要求。去离子水实验表明，当来流毛细数高达4.0×10^-3，高度为20 μm的微阀仍有效。

关键词:

毛细管被动阀, 通孔, 扩张角, 接触角