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Abstract：
In this paper, we investigate the electro-osmotic flow (EOF) and mass transfer of a Newtonian fluid propelled by a pressure gradient and alternating current (AC) electric field in a parallel microchannel with sinusoidal roughness and modulated charged surfaces. The two-wall roughness is described by in-phase or out-of-phase sine functions with a small amplitude δ. By employing the method of perturbation expansion, the semi-analytical solutions of the Poisson-Boltzmann (P-B) equation based on the Debye-Hückel approximation and the modified Navier-Stokes (N-S) equation are obtained. The numerical solution of the concentration equation is obtained by the finite difference method. The effects of sinusoidal roughness, modulated charged surface, and the AC electric field on the potential field, velocity field, and concentration field are discussed. Under the influence of the modulated charged surface and sinusoidal roughness, vortices are generated. The velocity oscillates due to the effect of the AC electric field. The results indicate that solute diffusion becomes enhanced when the oscillation Reynolds number is below a specific critical value, and it slows down when the oscillation Reynolds number exceeds this critical value.
摘要：
在本文中,我们研究了在具有正弦粗糙度和调制带电表面的平行微通道中，由压力梯度和交流（AC）电场推动的牛顿流体的电渗流（EOF）和传质。双壁粗糙度由具有小振幅δ的同相或异相正弦函数描述。通过采用扰动展开的方法，获得了基于Debye-Hückel近似和修正的Navier-Stokes（N-S）方程的Poisson-Boltzmann（P-B）方程的半解析解。用有限差分法得到浓度方程的数值解。正弦粗糙度的影响，调制带电表面，和电势场上的交流电场，速度场,和浓度场进行了讨论。在调制带电表面和正弦粗糙度的影响下，涡流产生。由于AC电场的影响,速度振荡。结果表明，当振荡雷诺数低于特定临界值时，溶质扩散增强。当振荡雷诺数超过这个临界值时，它会变慢。
