UNSTABLE PERIODIC MOTION IN PLANE COUETTE SYSTEM: THE SKELETON OF TURBULENCE

摘要

A recently discovered unstable time-periodic solution (Kawahara & Kida, J. Fluid Mech. 449, 291-300, 2001) to the incompressible Navier-Stokes equation for1 plane Couette flow is reviewed and recomputed with higher accuracy by use of the Newton-Raphson method to track the solution by changing the Reynolds number Re and the wall-parallel size of a computational periodic box It is found that the periodic motion, which exhibits a full regeneration cycle of near-wall coherent structures, appears through a saddle-node bifurcation and is traceable down to -Re RJ 290 The appearance of this periodic motion would be relevant to transition to turbulence in plane Couette flow.