Temporal correlation modification by microbubbles injection in a channel flow

In an effort to achieve a better understanding of the drag reduction mechanism by microbubbles injection, the structure of flow turbulence in a water channel with microbubbles is studied using particle image velocimetry technique (PIV) at Reh = 5128. Full field of the two-dimensional velocity components (streamwise and normal) within a location close to the wall was measured. The effects of several values of local void fraction upon the drag reduction are investigated.