Initial setting of the DD scenario. Left: evolution of the central density of both WDs during the relaxation (t ≤ 20 s) and the free evolving (t ≥ 20 s) stages. The orbital period is P ≃ 70 s. Right: slice in the orbital plane depicting the density color map of each white dwarf at t = 0 s (initial spherically symmetric configuration) and t = 20 s (final relaxed model). The slice has a thickness of four times the local smoothing length value (4 h). The center of mass of both configurations is located at (0, 0) km, but the snapshots have been shifted 14 000 km to the left and to the right to avoid the superposition of the images.