薄膜式气动微阀的流动特性研究

A Study on Flow Characteristics of Pneumatic Microvalves in Membrane Form

通过分析薄膜式气动微阀的内部流动特性,研究控制通道的驱动方式以及阀膜片结构对微阀耐压性和有效性的影响.建立不同微流道内控制方程和阀膜片的受力方程;计算压力驱动和速度驱动下微阀内部的流场特性,分析平展膜和波形膜的变形规律.搭建实验测试系统,测试不同入口速度下微阀的关闭性能.研究表明:压力驱动较速度驱动具有更好的控制性能,但容易造成阀膜片变形失效.波形膜较平展膜具有更好耐压性,并且可以增强控制的灵敏度和有效性.

This paper explores thedriving modes of the control channels and the effects of the diaphragm struc- tures on the pressure resistance and effectiveness of the microvalves by analyzing the internal flow characteristics of the membrane pneumatic microvalves. The governing equations of different micro fluidic channels and the stress equations of the diaphragms are established. The flow field characteristics of the microvalves are calculated and the deformation rules of the fiat films and the corrugated films are analyzed. An experimental test system to test the closing performance of microvalves at different inlet speeds is set up. The results show that pressure - driven model is better than velocity - driven model in terms of control performance, but it is easy to cause de- formation of the diaphragms. The corrugated films have better pressure resistance than the flat films and can en- hance the sensitivity and effectiveness of control.