Turbulent Structure and Relaminalization of a Rotating Turbulent Channel Flow at High Rotaton Number

The present study reports on a series of direct numerical simulation of turbulent rotating channel flows at rotation numbers higher than those previously reported. The bulk Reynolds number (Re) was set approximately constant at 5800, while the non-dimensional rotation number Ro was increased up to 5.79. The flow visualization showed that the structure of the enlarged eddies on the pressure side, and the orientation of the structure was inclined towards downstream. The investigation of the budget of Reynolds stress transport equation indicated that the pressure transport of Reynolds stress and re-distribution term were extraordinary large at higher Ro. This led the conventional decomposition of velocity-pressure correlation terms to being not appropriate in this flow. It is suggested that the Reynolds stress modeling should better target the correlation between velocity and pressure gradient, or pressure diffusion and re-distribution terms must be handled with the same efforts, which indeed increases the task of modeling.