In this project a number of challenging flow problems will be investigated by means of fully resolved numerical simulations. The flow problems investigated involve the thermal dynamics and transport of particulate matter in rarefied gases, the formation of droplets from fluid jets and in the chaotic flow of dense multicomponent fluid emulsions.

Turbulence is the wild, chaotic motion of air and water. At first blush, turbulence has no structure. But if constraints, like rotation, are added, a sharp transition appears between structureless turbulence and the growth of large-scale vortices. Such vortices are prominently visible in the atmosphere and oceans on our rotating planet. Researchers will study this effect in computer simulations to better understand and predict this transition. These insights are crucial for the modelling of large-scale natural flows like the motion of liquid iron in the core of the Earth, the source of its magnetic field.

Large-scale flows on Earth are forced by temperature differences and are affected by Earths rotation. Examples include the atmosphere and the flow in the liquid outer core. A laboratory experiment to study such systems necessarily has a finite size. Researchers investigate the effects of presence of sidewalls on the flows, to be able to better interpret results from these experiments. With this knowledge the translation from experiment to the large-scale natural flows can be performed more accurately.

In the present proposal we develop a parallel between seismic faulting and plastic events in soft-glassy materials below yield stress. We will employ a novel approach to study the dynamics of earthquakes based on an innovative continuum model displaying slip-stick dynamics. We will first compare our model against existing statistical models of earthquake frequency by changing model parameters. Second, we aim at establishing a quantitative statistical link between seismic surface measurements and micro-scale faulting events, as influenced by extraction events. Our project will allow a better understanding of the physics of soft-glassy material below yield and hopefully it will help shedding new light on the causal link between fluid extraction and seismicity.

As the interest in long-term modelling of sediment transport and morphodynamics in environmental flows increases due to concerns such as climate change and increasing human pressure, more emphasis has to be put on the understanding and modelling of the basic, though complex, physical processes involved. Sediment transport and morphodynamics are of crucial importance for many environmental and coastal engineering applications, and much advancement has been achieved in these areas. However, the effect of barotropic vortices has been seldom studied despite their ubiquity and importance in environmental flows like rip currents, flows in tidal basins, and flows behind solid obstacles such as piers and embankments. A comprehensive study is proposed to produce a complete and coherent theory of sediment transport by vertical vortices. Such structures have particular signatures and effects that must be understood to better model the erosion/transport/deposition of sediment in coastal areas. Without a better formulation of sediment dynamics, and in particular, the inclusion of barotropic vortex dynamics, the predictive capabilities of state-of the-art models will remain limited and the societal/governmental needs for prediction of changes due to human intervention might not be met. I propose to study well-controlled generic flow configurations that will allow us to model and understand several environmental situations. The proposed approach is composed of state-of-the-art laboratory experiments, direct numerical simulations, and numerical simulations using coastal ocean models. It is only through such a comprehensive approach that well known difficulties, like the scaling experimental results to real-world flows, can be tackled and a complete theory from small-scale laboratory experiments to the large-scale ocean can be achieved. This research and its results will be used to test and improve sediment transport and bed composition modules in coastal ocean models.