Particle suspensions in evolving Taylor-Green vortex flow

Abstract

Particle-laden flow is a ubiquitous phenomenon, observed in both natural and engineering settings. Most of the studies have focused on studying particles in standard flow systems, such as homogeneous isotropic turbulence (HIT) and channel flow. However, a common feature of these flows is the statistical steadiness, wherein the flow scales do not vary with time. This thesis takes a step further to explore the particle additives in an evolving Taylor-Green vortex (TGV) flow, whose flow scales are continuously changing. The spherical and non-spherical particles are tracked forward in time, along with the Eulerian evolution of the flow field. The particles are characterized by their inertia and shape, wherein the non-spherical ones are modeled as axi-symmetric ellipsoids, defined as prolate (rod-like) and oblate (disk-like) spheroids. A comprehensive study of particle dynamics with a wide range of shapes and inertia, in terms of clustering, preferential sampling, rotation and alignment with the flow is presented in this work. Additionally, the focus has also been to investigate the impact of continuously changing TGV flow scales on particle dynamics.