Evolution of the disk within one binary period for the fully radiative standard model. The top labels in the four panels state the current position of the binary (r_bin, ϕ_bin) in polar coordinates. In the first panel the binary companion is at the apastron and has less influence on the disk. The L₁ point in this configuration is at about 17.5 AU and therefore far outside the computational domain (gray circles). In the second panel the binary has reduced its distance to about 12.8 AU and the Roche lobe (green curve) has shrunken dramatically and is now entirely within the computational domain. The third panel shows the disk with the binary at periastron. Some of the material in the disk is now outside the Roche lobe and might be lost from the system. In the last panel the binary’s separation increases again, which makes the Roche lobe grow such that it engulfs the disk entirely. The strong tidal forces near periastron induce spiral waves in the disk that will be damped out until the binary is at apastron.