Heat transfer investigation of combined electroosmotic/pressure driven nanofluid flow in a microchannel: Effect of heterogeneous surface potential and slip boundary condition

摘要

In the present study, electroosmotic and pressure driven Newtonian nanofluid flow in a microchannel with constant temperature boundary condition is studied via Lattice Poisson-Boltzmann method. In order to validate the numerical solution, the computed results are compared with some existing analytical solutions. Then, effects of different parameters such as ratio of pressure velocity to Helmholtz-Smolochowski velocity, slip coefficient, nanoparticles volume fraction and diameter on flow field and heat transfer is examined. The results show that by fixing the electric field and increasing the pressure force, Nusselt number decreases, and it increases by fixing the pressure force and increasing the electric field. Also, increasing the slip coefficient causes the velocity enhancement in the electroosmotic flow. Furthermore, increasing the nanoparticles volume fraction decreases the velocity and increases Nusselt number. Finally heterogeneous surface potential moves the vortices toward the walls and enables controlling the quantity and direction of velocity field. (C) 2019 Elsevier Masson SAS. All rights reserved.