Properties of the velocity gradient tensor in a rotating turbulent channel flow

Direct numerical simulation (DNS) data of a wall-normal rotating turbulent channel flow are presented and analyzed at two rotation rates. The statistics show that rotation deflects the mean velocity vector towards the span of the channel and reduces turbulent kinetic energy. The influence of rotation on the properties of the velocity gradient tensor are analyzed, for the first time for thistype of flow, using its invariants and the invariants of the strain-rate tensor. Probability density functions (PDFs) at location of the peak of turbulence kinetic energy production are presented and the effect of rotation on these PDFs are discussed.

کلیدواژه ها:

Rotating channel ، turbulent flow ، velocity gradient tensor invariants