针对湿法刻蚀玻璃微通道截面具有圆角形状的特性,采用Fluent6.3软件,对以水为介质的圆角形微通道内的流动特征进行数值计算研究.基于层流流动模型,对不同雷诺数Re、不同形状因子下圆角形微通道的流动压降进行数值模拟；通过结果整理与分析,拟合圆角形微通道Poisueille数Po随截面形状因子α变化的经验公式,即Po=10.161 1-2.408 5α+0.166 0α2+0.480 9α3-0.197 9α4+0.023 4α5;对此经验公式在不同微通道截面和不同黏度流体流动条件下的适应性进行了验证.研究结果表明:雷诺数与截面形状对圆角形微通道流动压降有很大影响；当截面宽度一定时,压降随雷诺数和形状因子的增大而增加；在所研究的雷诺数范围内,圆角形微通道Poiseuille数不随雷诺数的变化而变化,而随截面形状因子的增大而减小；当雷诺数0.01≤Re≤40、截面形状因子0.4≤α≤3.2时,本文中介绍的圆角形微通道阻力系数经验公式均适用.%Numerical study was conducted on the flow resistance characteristics of water in semi-circle wet etched glass microchannels with Fluent 6.3. Numerical simulations were made to study the flow pressure drop at various Re numbers and aspect ratio α based on laminar flow model. An equation was obtained through the simulation results to describe the relationship between the Po number and the aspect ratio, i.e., Po=10.161 1-2.408 5a+0.166 0α2+0.480 9α3-0.197 9α4+ 0.023 4α5. Then several validations were conducted with microchannels of different geometric parameters and fluids of different viscosity.The results show that both Re number and aspect ratio have significant impacts on the flow pressure drop, i.e. the pressure drop increases with the increase of Re number and a when the width of the microchannel is constant. The Poiseuille number of the flow is constant within the range of Re number of interest, but it decreases with the increase of the aspect ratio. The equation is validated in the range of 0.01 ≤Re≤20,0.4≤a<3.2.
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