Relaminarized and recovered turbulence under nonuniform body forces

Abstract

We show that wall-bounded turbulence can be relaminarized and reorganized by adding nonuniform streamwise body forces. A nonuniform body force can distort the parabolic mean velocity profile, thus altering turbulence production due to mean shear. In the quasi-laminar state, all Reynolds stress tensor components are fairly weak except for streamwise fluctuations far from the wall, indicating a collapse of the near-wall turbulence self-sustaining cycle. In the recovered turbulence regime, the Reynolds shear stress has a negative range in the bulk connected with a positive range near the wall corresponding to the M-shaped velocity profile.