Suspensions of solid particles and liquid drops are ubiquitous in natural turbulent ﬂows: riverine discharges into the open ocean, marine snow (plankton and other carbonaceous matter) in the ocean, cloud droplets, spreading of volcanic ash and dust storms. In each of them there are physical questions of importance. This meeting will bring oceanographers, cloud scientists and fluid mechanicians studying particle and droplet transport together and those making observations in contact with modellers and theorists.
Plankton and other small living beings are found in relatively high concentration in the upper few metres of the ocean. The debris generated sinks to the deeper ocean, and has a major role in carbon sequestration. As they sink, hydrodynamic interactions and cohesive attractions between particles create larger particles of arbitrary shape. Droplets and ice crystals in a cloud need to come in contact and coalesce to grow into raindrops, and turbulence and gravity aid this process. Traditionally, particles in ﬂow have been studied in the Stokes and dilute flow limit, but these stringent assumptions are often not reasonable. It is time to understand the hydrodynamic interaction between particles, the dynamics of arbitrarily-shaped particles, and the role of the Basset-Boussinesq history force. Grain resolving models, high-resolution continuum models and methods accounting for particle history will be discussed, and the meeting will give an opportunity to evaluate how well they perform against measurements.
This meeting will consist of pedagogical and research sessions, and students doing research in related areas are encouraged to apply.