Transient dynamics at the onset of Taylor vortices

The effect of boundary conditions on the 'critical dynamics' at the onset of Taylor vortices is investigated in a combined numerical and experimental study. Numerical calculations of Navier-Stokes equations with 'stress-free' boundary conditions show that the Landau amplitude equation provides a good model of, the transient dynamics. However, this rapidly breaks down when the 'no-slip' condition is approached. Apparent 'critical' behaviour observed in experiments is shown to have a surprising dependence on the length of the system.