Exploring particle dynamics in anisotropic and inhomogeneous turbulent flows
Turbulence is a widespread phenomenon, involved in processes such as ocean currents and different industrial flows. Traditional studies often assume isotropic and homogeneous turbulence (HIT), yet real-world conditions frequently deviate from this idealisation. In my presentation I will explore the dynamics of various types of particles in turbulent flows that exhibit some degree of anisotropy or inhomogeneity. By comparing three-dimensional trajectories of tracer particles in a von Kármán (VK) experiment with Lagrangian particles in Taylor-Green (TG) flow numerical simulations, we find striking similarities in their dynamics. This allows us to asses the impact of a mean flow on different particles’ statistics. We further extend this study to the reconstruction of flow topology from measurable quantities like tracer particles’ trajectory crossings, revealing a direct link with the flow kinetic helicity. We take advantage of the parallels between VK and TG flows to evaluate effective models of finite-size particles with inertia. We analyse the clustering of these types of particles and how this phenomenon is related to the geometrical properties of the carrier flow. The study of particle dynamics in the two flows considered sheds light on how turbulent flows with a large scale structure affect the dynamics of tracers and inertial particles, and conversely provides insights on what we can learn of the carrier flow from particle data.
