D37.00004. The onset of turbulence: from invariant solutions to a directed percolation phase transition
Presented by: Bjoern Hof
Flows through pipes and channels exhibit an abrupt transition from ordered laminar to high dimensional turbulent flow. At the lowest Reynolds numbers where this transition can be observed the resulting flows are spatio temporally intermittent and are composed of patches of turbulence surrounded by laminar fluid. As will be shown, in direct numerical simulations individual turbulent patches (i.e. stripes and puffs) can be continued to much lower Reynolds numbers where they originate from spatially localized periodic orbit solutions. I will further discuss experimental studies of interacting turbulent patches and how the competition between the decay and the proliferation of turbulence gives rise to a phase transition to sustained turbulence.
- Bjoern Hof