We study the evolution of the superfluid starting from two initial conditions consisting of straight vortex lines and circular vortex rings, respectively. For both initial conditions, videos of the time evolution of the vortex-line tangle and of the occupation number spectrum are provided at the links below.
A video of reconnecting vortex lines and shrinking vortex rings for a simple initial configuration of only four straight vortex lines is provideded at the link below.