How does flow in a pipe become turbulent?
University of Marburg
The routes to turbulence in many flows comprise series of transitions
that introduce more and more temporal and spatial variations until the
spatially and temporally disordered state we call turbulent is obtained.
Flow in a pipe does not fit into this scheme, as theory and experiment
do not show any sharp transitions. Building on experience in dynamical
systems we have proposed a scenario that involves certain types of
waves and a strange saddle. This model is in good agreement with
experiments and numerical simulations.