The present work studies heat transfer of the gas fluid in open microchannels at constant wall heat flux boundary conditions. The proposed model assumes the fluid is a continuum, but employs a slip boundary condition on the channel wall. Using appropriate similarity variables, the fundamental equations of the boundary layer are transformed to ordinary differential equations containing a Prandtl number. These ordinary differential equations are solved numerically using a fifth order Runge-Kutta and shooting method. Consequently, the velocity profiles, the temperature profiles, the wall shear stress and the local Nusselt number exhibit a dependence on the slip coefficient. The results illustrate that the thermal creep term has a very small effect on the solution. It is shown that laminar boundary layer of gas fluid with slip flow tends to increase near wall fluid axial velocity and temperature jump on the wall as the flow becomes more rarefied. It will be seen that heat transfer in open microchannels is affected with temperature jump more than slip velocity under constant wall heat flux boundary condition.

Keywords