Workshop on inertial particles in turbulence: theory and applications from engineering to geophysics

It is well known that even in a homogeneous turbulent flow, inertial particlescan form clusters, or inhomogeneities, on account of the small-scale variationof the homogeneous turbulent fluid and the finiteresponse time of the inertial particles to these changes.This generates a rich variety of patterns that have been the subjectof much research over several decades. There aremany contexts in which this problem manifests itself, in fluidised bedswhich are of interest to the chemical engineering and nuclearpower industries, in sedimentation in rivers, in spray droplets in engines,in the creation of powders in the pharmaceutical industryand in the formation of clouds. There is thus considerable expertiseon this issue across a wide range of disciplines.Despite a wealth of understanding on inertial particles in turbulencedeveloped over many years of research, there remain several outstandingproblems. These include the role of acceleration, the effect of collisionsand how the particle statistics vary with the Stokes number, the dimensionlessnumber which characterises how closely the inertial particlesfollow the turbulent fluid. In various industrial, environmental andgeophysical situations forces such as gravity, centrifugaland Coriolis forces and even electromagnetic forces canbecome important and may change the variation of the particlestatistics with the Stokes number. A further issue in both engineeringand geophysical situations is the impact of these inhomogeneities onevaporation of droplets and heat transfer including radiative heating.The aim of this workshop is to bring together those working oninertial particles in turbulence in both engineering and geophysicalsituations to assess the current state of knowledge,plan future research and foster collaboration.It is through the interaction of these diverse but overlapping disciplines thatwe hope to produce some answers to the questions posed above.