LAUSR

Abstract The natural convection of a paramagnetic fluid is numerically investigated in the presence of a magnetic field from a block permanent magnet. One vertical wall of a cavity is partially heated at a constant heat flux to consider a single vertical heated wall. The permanent block magnet is placed behind the heated wall, of which the magnetic field is numerically obtained. Since the magnetic force is remarkable at edges of the block magnet, the magnetothermal force is also pronounced if the temperature difference exists by wall heating. The overlapping magnetothermal force works to repel the fluid. This results in the heat transfer enhancement near the upper magnet edge, and suppression near the lower magnet edge. The suppressing effect becomes remarkable rather than the enhancing one in cases of large magnetic induction, high wall heat flux, and high magnet elevation to the heated wall.