弯曲微槽道内流场的PIV测量和数值模拟

PIV measurement and simulation in a curved microchannel

利用micro-PIV和CFD数值模拟研究水力直径为220μm正方形截面弯曲微槽道中的流动特性。实验中利用micro-PIV测量了槽道中5个不同深度流场,雷诺数为Re=42,91和239。实验测量和数值模拟相吻合,弯曲的微槽道不同截面处存在由二次流诱发的Dean涡,并随Dean数的增加,涡结构更加复杂;Dean涡对截面内两种液体接触面会产生影响,所以可以通过利用Dean涡的发展加强微管道中的混合。

In this article, micro-PIV and CFD （computational fluid dynamics） simulation were used to research the characteristics of flow in a curved microchannel whose hydraulic diameter is 220μm. In the experiment velocity distributions of flow fields at five different depths in the microchannel were measured with micro- PIV, when the Reynolds numbers were 42, 91 and 239 respectively, rllae experiment results agreed with the results of simulation well, there were Dean Vortices induced by secondary flow on the cross sections, and the vortices turned to be more complicated as the Dean number increases, The Dean vortices have influence on the interface of two kinds of liquid, so the mixture in microchannel can be strengthened by the development of Dean vortices.