Slip length of confined liquid with small roughness of solid-liquid interfaces

摘要

We have studied the slip length of confined liquid with small roughness of solid-liquid interfaces. DyadicGreen function and perturbation expansion have been applied to get the slip length quantitatively. In the sliplength, both the effects of the roughness of the interfaces and the chemical interaction between the liquid andthe solid surface are involved. For the numerical calculation, Monte Carlo method has been used to simulate therough interfaces and the physical quantities are obtained statistically over the interfaces. Results show that thetotal slip length of the system is linearly proportional to the slip length contributed from the chemical interaction.And the roughness of the interfaces plays its role as the proportionality factor. For the roughness, the variance ofthe roughness decreases the total slip length while the correlation length of the roughness can enhance the sliplength dramatically to a saturation value.