Results for the three-dimensional static ring problem. The top panels correspond to the contour of temperature at the initial and final stages, together with the magnetic field lines, obtained with the simulation with scheme #1. Bottom left panel shows a comparison of one snapshot of the temperature at x = −0.5 and y = 0.21 at t = 10 for different simulations using scheme #2 and different time steps. In the bottom right panel, a graphical representation of the computational times of the different runs is given.