DNS Study of Transitional Channel Flow Accompanied by Turbulent-Stripe Structures

A regular pattern of turbulent and quasi-laminar fluid motion is known to appear in plane Poiseuille flow near the lowest Reynolds number for which turbulence can be sustained. We focused on this transitional structure called the turbulent stripe and investigated its energy transport process, using a direct numerical simulation. We obtained the budget for Reynolds stresses including v^′w^′ and w^′u^′. The spatial outline of the energy transport with respect to the turbulent stripe is proposed. The turbulent energy is produced in both the turbulent region and the quasi-laminar region, and the energy transfer between these two regions is found to be small.