With their ubiquitous occurrence in a multitude of fluid systems bubbles occupy a very important place in contemporary science and technology. One can readily cite a multitude of examples: the production and transport of oil (where bubbles are purposely injected to help lift heavy oil to the surface), energy generation (where boiling is the key process in producing the steam to drive turbines), the chemical industry (where gas-liquid reactors rely on bubbles to increase the contact area between the phases), the oceans (where breaking-wave generated bubbles are important sinks for atmospheric CO2), piezo-electric ink-jet printing (where they are just disturbing), bubble chambers in high-energy physics (where they used to signal the traces of energetic particles), and many others.

Due to the improved experimental and computational techniques there has been rapid progress in the field in the last decade. E.G., simulating a few rising, deformable bubbles in still water is meanwhile possible. Also a lot of theoretical insight has been gained. However, many questions remain open. This holds both for a single bubble, e.g., what is the lift force on a single bubble in shear or rotational flow, and for many bubbles, e.g., how do many bubbles in turbulent flow modify the spectrum? Various experimental and numerical results on these questions have been obtained, but they often seem to contradicting to each other, presumably as the exact conditions are different.

The idea of the Workshop at the Lorentz Center in Leiden and the Euromech Colloquium in the beginning of the Workshop is to bring together both experimentalist, theoreticians, and simulators of the fundamentally orientated bubbly flow community to allow for an exchange of ideas on the recent developments in this field.