TY - JOUR JF - mdrsjrns JO - Modares Mechanical Engineering VL - 15 IS - 4 PY - 2015 Y1 - 2015/6/01 TI - Investigation of Mixing in Electroosmotic Micromixers using Nernst-Planck Equations TT - بررسی اختلاط در ریزمخلوط گرهای الکترواسموتیکی با حل معادلات ارنست-پلانک N2 - Mixing within electrokinetic micromixers is studied numerically in this article. Micromixer studied here is simply a heterogeneous parallel plate microchannel which is imposed to the electroosmotic flow field. For the through modeling of such flows, the coupled equations of Navier-Stokes, Nernst-Planck, Poisson-Boltzmann and concentration equations are solved for the flow motion, electric charges transport, electric field and species concentrations, respectively. Numerical solution of these set of equations for the heterogeneous microchannels is complicated and difficult. Therefore, simple and approximate model such as Helmholtz-Smoluchowski has been proposed which is basically appropriate for the case of microchannels with the homogenous properties on the walls. Validation of Helmholtz-Smoluchowski model is well-examined for the prediction of two dimensional flow fields, yet its applications is rarely validated for the prediction of concentration field and mixing performance. In this article mixing due to electroosmotic flow field is investigated using Nernst-Planck equations as well as Helmholtz-Smoluchowski models and the accuracy of the Helmholtz-Smoluchowski model is evaluated. Comparison of the results indicates that for the proper conditions, approximate model can predict the mixing performance accurately along the micromixer length. SP - 203 EP - 213 AU - Jamaati, Jafar AU - Farahinia, Ali Reza AU - Niazmand, Hamid AD - Department of Mechanical Engineering, Ferdowsi University of Mashhad KW - Mixing KW - Micromixer KW - Nernst-Planck equations KW - Electroosmotic flow KW - Helmholtz-Smoluchowski Model UR - http://mme.modares.ac.ir/article-15-9262-en.html ER -