The dynamics of bursting process in wall turbulence

We have examined bursting processes observed in turbulent channel flow by d irect numerical simulation of the incompressible Navier-Stokes equations in a minimal flow unit. A traveling wave solution (TWS) is obtained by a shoo ting method. The TWS corresponds to a saddle point in a two-dimensional pha se space. A low-dimensional dynamics confined to the near-wall region is pr oposed in terms of the TWS and its manifolds. The characteristics of the co herent structures constituting the TWS are investigated dynamically and sta tistically in detail. The dynamics well describes an elementary process of intermittent turbulent regeneration in wall turbulence.