kth_logo.gif

Artikel

Formation of turbulent patterns near the onset of transition in plane Couette flow

Författare: Duguet, Y., Schlatter, P., Henningson, D.S.H.
Dokumenttyp: Artikel
Tillstånd: Publicerad
Tidskrift: J. Fluid Mech.
Volym: 650   119-129
År: 2010

Abstract

The formation of turbulent patterns in plane Couette flow is investigated near the onset of transition, using numerical simulation in a very large domain of size 800 h× 2 h × 356 h. Based on a maximum observation time of 20 000 inertial units, the threshold for the appearance of sustained turbulent motion is Rec =324 ± 1. For Rec <380, turbulent-banded patterns form, irrespective of whether the initial perturbation is a noise or localized disturbance. Measurements of the turbulent fraction versus Re show evidence for a discontinuous phase transition scenario where turbulent spots play the role of the nuclei. Using a smaller computational box, the angle selection of the turbulent bands in the early stages of their development is shown to be related to the amplitude of the initial perturbation.