Electroosmotic Flow Separation in a Corrugated Micro-Channel: A Numerical Study

A two dimensional numerical study is made on the electroosmotic flow separation and vortex formation in a symmetric wavy micro/nano channel filled with a Newtonian, incompressible electrolyte. Flow domain is modelled by two superimposed sinusoidal functions which is mapped into a simpler rectangular computational domain using a suitable coordinate transformation. The distributions of flow field and electric potential are obtained by solving a coupled set of nonlinear governing equations involving Poisson-Nernst-Planck equation and Navier-Stokes equation using finite volume method. Threshold value of the scaled wave amplitude for flow reversal is obtained for fixed Debye-Hückel parameter and solute strength where flow separation plays a vital role for micromixing which can be a major interest for many research problems of biological flows.