The nonlinear flow of liquids through nanoscale channels play an important role in the separation and purification properties of porous membranes, the manufacture of biofilm ionic channels and microfluidic chips, the production of micro electro-mechanical systems. Silicon oil flow experiments were conducted through anodic alumina films with pore sizes of 26, 67, 89, and 124 nm, in which flow mechanism and characteristics of the oil through the nanoscale channels were analyzed. Four nanoflow features are revealed: (1) The experimental flow rate is less than the theoretical flow rate through nanochannels, as solid-liquid interaction increasing flow resistance. (2) At small shear rate, the boundary layer is one, indicating existence of a threshold pressure of oil flow through nanochannels. (3) The boundary layer decreases with the increasing of shear rate, and it rapidly decreases as shear rate increases when the value of shear rate is small. (4) The drag coefficient decreases nonlinearly with increasing shear rate, decreasing more slowly when value of shear rate is big, and trending towards 1 in the case of large shear rate. It is shown that the non-linearity of flow is induced by great solid-liquid interaction in nano and microscale, and increasing the driving force can raise the efficiency at the nanometer scale.

液体通过纳米级通道的非线性流动在多孔膜的分离和净化性能、生物膜离子通道和微流控芯片的制造、微机电系统的生产中起着重要作用。通过孔径为26、67、89和124 nm的阳极氧化铝薄膜进行硅油流动实验，分析了油通过纳米级通道的流动机制和特性。揭示了四个纳米流特征：（1）实验流速小于通过纳米通道的理论流速，因为固液相互作用增加了流动阻力。(2) 在小剪切速率下，边界层为一层，表明存在油流过纳米通道的阈值压力。(3)边界层随着剪切速率的增加而减小，当剪切速率值小时边界层随着剪切速率的增加而迅速减小。(4) 阻力系数随着剪切速率的增加呈非线性减小，剪切速率大时减小速度较慢，剪切速率大时趋向于1。结果表明，流动的非线性是由纳米和微米尺度的固液相互作用引起的，增加驱动力可以提高纳米尺度的效率。