周期壁面电势调制下平行板微管道中的电磁电渗流动

研究了平行板微管道中二维磁流体(MHD)电渗流(EOF)在zeta电势调制下的流动.流体的流动是由两个外加水平电场和垂直磁场所产生的Lorentz力和电场力的组合驱动的.在滑移边界条件下,得到了流函数以及速度分布的解析解.详细讨论了速度随Hartmann数Ha、滑移长度B、电动宽度K等相关的无量纲参数量级变化的变化规律.结果表明,调制的壁面电势会产生一个垂直速度分量,从而导致涡旋的形成.此外,可以观察到,速度的大小随着滑移长度B和电动宽度K的增大而增大.值得注意的是,速度的大小随着Ha值的增大而减小,这与一维流动中Ha值存在临界值的情况不同.

Magnetohydrodynamic Electroosmotic Flow in Zeta Potential Patterned Micro-Parallel Channels

Two-dimensional magnetohydrodynamic(MHD)electroosmotic flow(EOF)in zeta potential patterned micro-parallel channels was studied.The flow was driven by the combination of the Lorentz force and the electric field force produced due to an externally imposed vertical magnetic field and two horizontal electric fields.The analytical solutions of stream function and velocity distribution were obtained under the condition of hydrodynamic slippage.The variations of velocities with related non-dimensional parameters,such as Hartmann number Ha,slip length B and electrokinetic width K were addressed in detail.Results show that,the patterned charged surfaces induce a vertical velocity component leading to the formation of the vortexes.Also,the magnitudes of velocities increase with slip length B and electrokinetic width K.Moreover,it is interesting to note that the magnitudes of velocities become small with the increasing value of Ha,unlike the situation where there exists a critical value of Ha in one-dimensional flow.The present theoretical results can be utilized to design efficient microfluidic devices.