Study On Liquid Flow Characteristics In Circular Glass Microchannels

Microchannel is an important component as one of the micro fluid system. Because of its small size, the micro channel making method and liquid flow in microchannel with a unique phenomenon. So the structure of the microchannel and micro fluid flow characteristics has become hot research topics.The glass microchannels were obtained with vitreous bionic micro channel fabricating device. The flow characteristics of deionized water and ethyl alcohol in glass microchannel were studied by experiments and numerical simulations. And analyzed the changing tendency of parameters. The main contents are as follows:1)To complete the design of the experimental system, mainly including the experimental pressure driven device, microchannel inlet and outlet pressure difference and flow measurement, and to ensure that the experimental system of air tightness.2)Based on vitreous bionic micro channel fabricating device, through parameter settings to complete the excellent feature sizes flat microchannel. Then measurement of microchannel diameter, outside diameter and length. And the flow rates of microchannels with diameters in the range of 14-125 ?m were measured.3)Determining the fluid used in the experiment, finishing the experiments on flow characteristics in micro channel and measuring the inlet pressure and outlet flow rate of the microchannel. By using the mature CFD software”FLUENT”, simulation of flow characteristics in microchannels. Analyzed and studied flow characteristics of different pressure and different diameter. Relationships between the flow and the pressure difference at the outlet of microchannel, resistance coefficients and Reynolds numbers,Poiseuille numbers and Reynolds numbers were comparatively studied using both method of simulation and experiment respectively.4)The experimental and numerical simulation results show that the flow rate increase with the increase of the pressure; the friction factor increase with the increase of the Reynolds number and less than theoretic value. The Poiseuille number is a constant in the experimental and numerical simulation and also less than theoretic value. It also shows that the Poiseuille number only dependent on the shape of microchannel. Due to the different between the microchannel for numerical simulation and experimental microchannel,experimental results and numerical simulation results are not same exactly.