This work provides a mathematical model for the cooling process of a moving surface, in
the presence of a uniform external magnetic field and thermal radiation, through a porous medium by
using a weak concentration micropolar nanofluid. The model—based on the conservation equations
of the unsteady case in the momentum and thermal boundary layer—takes into consideration the
effect of the suction process. The conservation equations were transformed into ordinary differential
equations using similar transformation techniques. The equations were solved numerically for the
general case and analytically for the steady case. The rate of heat transfer, couple shear stress, and
surface shear stress are deduced. We discuss the impact of these physical characteristics on the
mechanical properties of the surface that will be cooled.