Experiments About Simple Liquid Flows in Microtubes

The behavior of micro-scale flow is significant for the performance of Micro-Electro-Mechanical-Systems (MEMS) devices. Some experiments about liquid flow through microtubes with diameters about 3∼20μm are presented here. The liquids used in our experiments include some simple liquids with small molecules, such as non-ion water and several kinds of organic liquids (CCL₄, C₆H₅C₂H₅ and Isopropanol etc.). The flow rate and the normalized friction coefficients were measured in micro-flow experimental apparatus. The results show that when the driven pressure varies from 0 to 1Mpa, the flow behaviors in 20μm microtube for both polar and non-polar liquids are in agreement with Hagen-Poiseuille law of the classical theory. It means that N-S equation based on continuous medium still acts well in this case. For higher pressure drop from 1 to 30Mpa, in the microtubes with diameter of 3∼10μm, the normalized friction coefficients of organic liquids can’t keep constant with pressure increases. However the non-ion water reveals different trends.