Time and Spatial Pressure and Velocity Correlation in a Microbubble Laden Boundary Layer

Measurements of the velocity fields and wall pressure have been performed in a microbubble laden boundary layer in order to have a better understanding of the degree of correlation between these two parameters. Cross-correlation coefficients have been obtained from synchronized measurements of pressure and velocity at different distances from the wall in a channel flow. The results show a high correlation between pressure and both the streamwise and normal components of the velocity vector for the two-phase flow case. In contrast, the correlation coefficient between pressure and velocity is high only for the streamwise component of the velocity vector for single phase flow (no microbubbles in the flow). A practical application of these measurements is obtaining data and information to better describe the mechanism responsible for the microbubble drag reduction phenomenon, which has great potential for energy savings on different transport means.