微流道粗糙壁面对流动阻力和控制的影响

Effects of surface roughness of microchannel on drag reduction and control

研究了3种粗糙单元(三角形、矩形、三角形与矩形交错混合)壁面对微流道内流动和摩擦阻力的影响。利用二维模型模拟了量纲一泊肃叶数与粗糙单元的几何特性和分布的关系。结果发现:在模拟条件下,粗糙壁面摩擦阻力(泊肃叶数)总是大于光滑壁面的摩擦阻力;壁面粗糙单元的高度对摩擦阻力的影响较大,可有近乎指数型的增长,粗糙单元的长度和间隔的影响居中,而雷诺数的影响较小。说明壁面粗糙度可有效改变槽道内的流动状态,增大混合效率。

The effects of surface roughness elements in different shapes, i.e. triangle, rectangle and their intermixing shape, on the plane microchannel flows and the frictional drag were studied. The two-dimensional numerical results show that the channel with rough surface always leads to a higher flow friction than that with smooth surface. Under the conditions of present study, it shows that the height of rough elements has the biggest influence on drag increase, the width and the space between of elements place is the middle, and Reynolds number is least. The above results indicate that the surface roughness can be applied to effectively control microchannel flow and enhance the efficiency of mixing.