Bubble plumes beneath an inclined wall*

Bubbles injected beneath a submerged inclined wall can form a two-dimensional plume, entraining surrounding liquid and spreading out laterally as they rise along the wall. These plumes are being considered as a technique for preventing biofouling in marine environments, for example on ship hulls. We use high-speed imaging experiments to obtain ensemble statistics and bubble trajectories, allowing us to investigate how the bubble plume structure and velocity depend on flow rate, nozzle size, and inclination angle. The results are compared to integral plume theory and previous studies of axisymmetric bubble plumes.