基于解析法的微锥孔流动特性计算

为了优化微锥孔的设计,推导了一种计算渐缩/渐扩流动的解析算法;并与数值计算方法进行了对比,发现解析方法可以满足层流的渐缩/渐扩流动精度。在计算渐缩/渐扩流场的基础上,给出了流动阻力的计算方法,分析了流动阻力和雷诺数及角度的关系。研究发现流动阻力最小的并不是锥角为0的区域,而是出现在角度较小的渐扩流中;且随着雷诺数的减小,最小流阻出现的角度越大。研究结果可以为基于渐缩/渐扩流动的微型泵、喷射及雾化系统的设计提供参考。

Flow Characteristic Calculation of Nozzle/Diffuser Flow by an Analytical Method

In order to optimize the structure of nozzle in microfluidics device, an analytical method for calculating the nozzle/diffuser flow is deduced and compared with the numerical calculation method. It is found that the analytical method can satisfy the laminar flow''s nozzle/diffuser flow accuracy. Flow resistance is calculated on the basis of the nozzle/diffuser flow field, and the relationship between flow resistance and Reynolds number and angle is analyzed. It has been found that the flow with lowest flow resistance is not the parallel flow, but the diffuser flow with a small taper angle, and the taper angle with lowest flow resistance decrease with the Reynolds number. The research results will be helpful to the designs of micropumps, jets and atomization systems based on nozzle/diffuser elements.