Direct numerical simulation of turbulent Taylor-Couette flow

We investigate the dynamical and statistical features of turbulent Taylor-Couette flow (for a radius ratio 0.5) through three-dimensional direct numerical simulations (DNS) at Reynolds numbers ranging from 1000 to 8000. We show that in three-dimensional space the Gortler vortices are randomly distributed in banded regions on the wall, concentrating at the outflow boundaries of Taylor vortex cells, which spread over the entire cylinder surface with increasing Reynolds number. Gortler vortices cause streaky structures that form herringbone-like patterns near the wall. For the Reynolds numbers studied here, the average axial spacing of the streaks is approximately 100 viscous wall units, and the average tilting angle ranges from 16 degrees to 20 degrees. Simulation results have been compared to the experimental data in the literature, and the flow dynamics and statistics are discussed in detail.