We report a study on the micro-confined electroosmotic flow of an Oldroyd-B fluid over a surface having asymmetric charge modulation. We have employed a combination of regular and matched asymptotic expansion to obtain the analytical solution. We have also carried out a full numerical simulation of the physicochemical problem in order to assess the full parameter space of the problem. The analytical solution is shown to be in excellent agreement with the full numerical solution in the limiting conditions of thin electrical double layers and weakly viscoelastic fluids. We have used these solutions to describe the complex fluid flow pattern and the modified electroosmotic slip velocity. We have also highlighted the alteration in the net volumetric throughput and ionic current. We have subsequently presented the numerical solutions for the velocity field, flow rates, and streaming current by varying the physicochemical conditions at the surface and viscoelastic properties of the fluid. We report an augmentation in the electroosmotic slip velocity with the increase in relative strength. The symmetry breaking of flow and stress distributions are shown to affect the net-throughput and streaming current, which is indicative of the combined effect of phase angle, magnitude of charge distribution, and the fluid viscoelasticity. We have shown that the thickness of electrical double layer considerably affects the net-throughput and streaming current generation in the microchannel. Our results hold the key towards understanding the complex bio-fluid transport in a microchannel utilizing the electric field in the presence of non-uniform surface charge distribution.

我们报告了关于Oldroyd-B流体在具有不对称电荷调制的表面上的微约束电渗流的研究。我们采用正则和匹配渐近展开的组合来获得解析解。我们还对物理化学问题进行了完整的数值模拟，以评估问题的完整参数空间。在薄的双电层和弱粘弹性流体的极限条件下，分析解决方案与数值解显示出极好的一致性。我们已经使用这些解决方案来描述复杂的流体流动模式和修改后的电渗滑移速度。我们还强调了净体积通量和离子电流的变化。随后，我们通过改变流体表面的物理化学条件和流体的粘弹性，提出了速度场，流速和流动电流的数值解。我们报道电渗滑移速度随着相对强度的增加而增加。流动和应力分布的对称破坏表明会影响净吞吐量和流动电流，这表明相角，电荷分布量和流体粘弹性的综合作用。我们已经表明，电双层的厚度会显着影响微通道中的净吞吐量和流式电流生成。