Lattice Boltzmann simulation of thermal electro-osmotic flows in micro/nanochannels

Electro-osmotic flows in micro/nanochannels usually present a temperature gradient arising from internal Joule heating and viscous dissipation. In this paper, we propose a lattice Boltzmann BGK (LBGK) model for heat transfer in micro/nanoscale electro-osmotic flows. The proposed model was validated by simulation of the constant-property electro-osmotic flow under both isothermal and thermal conditions; the numerical results are in good agreement with analytical solutions. We applied the LBGK model to simulation of the mixed electro-osmotic/ pressure-driven flow and heat transfer with temperature-dependent fluid properties and found that Joule heating exerts a significant effect on electro-osmotic flows and the effect of viscous dissipation becomes significant as the dimension of channel reduces to the nanometer scale.