Impact of asymmetric zeta-potential on natural convection flow in a vertical microannulus with electroosmotic and Joule heating effects

Analytical solutions of temperature distributions and flow formation of joint buoyancy and electroosmotic flow in a vertical microtube formed by two concentric microcylinders are presented. The central equations describing flow formations and thermal energy are offered and solved in closed-form in terms of modified Bessel's function of first and second kinds. These solutions have significant application in predicting and analyzing flow formation and thermal behavior of Newtonian fluids in micropumps and microchips. Based on the exact solutions obtained, the effects of flow parameters are clearly explained with the use of line graphs. Based on the simulation of results using MATLAB, it is found that fluid temperature distributions and fluid velocity in the vertical microannulus could be enhanced by increasing the radius ratio of the concentric microcylinders.