The two-way coupled interaction of bubbles with the turbulent flow is not well understood. The studies that have been done generally focus on the integral/global properties of turbulence, and there have been almost no studies on the local/bubble-scale viewpoint. To address this, we experimentally study the two-way interaction of a single bubble with naturally occurring bubble-scale vortical structures present in a fully developed horizontal turbulent channel flow. These interactions are directly measured using time-resolved particle image velocimetry, enabling links between the vortical structure evolution and the bubble trajectory in such flows. We observe that for the same bubble diameter Db and channel flow Reynolds number Re, but for different realizations, bubbles injected at the bottom wall have three broadly different types of bubble paths, which include sliding along the wall, bouncing motions, and vertical escape from the vicinity of the wall. The time-resolved vorticity field measurements show that these bubble trajectories are a direct result of the interactions of the bubble with the evolving vortical structure present in the vicinity of the bubble. This is also illustrated using a simple Lagrangian particle tracking model for the bubble in the vicinity of an evolving vortical structure.
Jha et al. (Thu,) studied this question.