Statistics of Turbulence in Cylindrical Flow

To investigate why the current turbulent models cannot represent shaking behaviors in the wake of turbulent cylindrical flow, the three-dimensional direct numerical simulations of incompressible cylindrical flow were performed. We used Lagrangian inertia-less particles to collect the information of turbulent fields, and discussed the features of diffusion of disturbs near the cylindrical walls. It was found via the numerical experiments that: 1) Fluctuations of turbulent kinetic energy and dissipation rate of kinetic energy occurred in the cases of higher Reynolds numbers; this behavior may be caused by the disturbs from the walls. 2) It was expected that directions of Reynolds stress and macro-scale strain of fluid velocity are aligned or independent, but this pre-杨静远，丁桦