Wavelength selection of turbulent bands in transitional turbulence

Transition to turbulence in shear flows is characterized by oblique turbulent bands. In plane Couette flow, a spacing of λ=40h between the bands naturally arises from featureless turbulence. Below 40h, turbulent bands interact too strongly to coexist naturally, but can be produced in periodic domains of restricted lengths and fixed tilt. The stability of such fixed-wavelength patterns is studied as a function of Reynolds number, as well as the mechanisms giving birth to a wavelength selection from featureless turbulence.