The combined effect of viscous dissipation and Brownian motion, especially on temperature distribution and heat transfer, has been carried out. Results show that there is an increase in temperature values throughout the field with the increase in the Eckert number Ec, this can be proven by the additional source of thermal energy (heat) provided by viscous dissipation in the porous medium, but it makes a decrease in heat transfer. For a lower Darcy number Da, the Brownian motion effect is negligible. Without Brownian motion, the averaged Nusselt number reveals an increase when nanoparticles volume fraction