CREDITS: Wai Hong, Ronald Chan, Shahab Mirjalili, Suhas Jain Suresh, Javier Urzay, Ali Mani and Parviz Moin, Center for Turbulence Research, Stanford University

Naturally-occurring and ship-generated turbulent breaking waves in the ocean generate bubbles of a wide range of sizes. Of these, the smallest microbubbles persist for a long time and have a long-lasting impact on the oceanic environment and on the visual and acoustic traceability of ships. In order to investigate the formation of these microbubbles, massively parallel high-fidelity numerical simulations of each of the stages in this multi-scale formation process are performed.

These simulations lend credence to a model pathway for the birth of these microbubbles, involving processes that span over a wide range of scales and consist of collisions between liquid bodies, turbulent air entrainment, and breakup of entrapped air films.