MHD free convection flow in a vertical slit micro-channel with super-hydrophobic slip and temperature jump: Heating by constant wall temperature

Abstract

This work treats convective heat transfer, for an incompressible electrically-conducting fluid, moving vertically through an isothermally heated parallel plate micro-channel, within a transverse magnetic field. One surface exhibited super-hydrophobic slip and temperature jump, while the other did not. The study aimed at discovering the possible effects of magnetism on the velocity, volume flow rate and Nusselt Number when either wall is heated by constant wall temperature. It was noted that it reduces velocity and flow rate in both cases. It, also, leads to decline in Nusselt Number when the super-hydrophobic side is heated, while heating the other plate showed a negligible magnetic effect, for low temperature jump coefficients. At the critical value of the temperature jump coefficient, γ, the flow rates in both cases are equal. Before the critical value (γcrit.) is reached, heating the super-hydrophobic plate yields higher flow rate. After passing it, the reverse is the case. The effect of magnetism on γcrit. was, also, negative. The study will have applications in the design and maintenance of both mini- and micro-devices as well as in nano-science and nano-technology.