Thermally fully developed electroosmotic flow through a rectangular microchannel

摘要

This study investigates the velocity and temperature distributions of the thermally fully developed electroosmotic flow through a rectangular microchannel. Based on linearized Poisson-Boltzmann (PB) equation, Navier-Stokes equation and thermally fully developed energy equation, analytical solutions of normalized velocity, temperature and Nusselt number are derived. They greatly depend on the ratio K of characteristic scale of the rectangular microchannel to Debye length, width to height ratio a and Joule heating to heat flux ratio S. By numerical computation, we found that for prescribed electrokinetic width K, increased S yields greater temperature. For small K, the variations of the temperature θ are larger than those of large K. The dependence of temperature on S is more significant for a small K, while at a larger K the temperature profiles are almost identical. In addition, we illustrate the Nusselt number Nu variations with S, a and K.