Influence of the history force on inertial particle advection: Gravitational effects and horizontal diffusion

TL;DR

This paper investigates how the Basset history force affects the movement and distribution of inertial particles in convection flows, revealing significant changes in attractor dynamics, basin fractalization, and sedimentation speed.

Contribution

It provides the first detailed analysis of the history force's impact on particle advection, highlighting its role in altering attractor structures and diffusion in fluid flows.

Findings

History force alters the number and nature of attractors.

It weakens horizontal diffusion of particles.

The effect is more pronounced for larger particles.

Abstract

We analyse the effect of the Basset history force on the sedimentation or rising of inertial particles in a two-dimensional convection flow. When memory effects are neglected, the system exhibits rich dynamics, including periodic, quasi-periodic and chaotic attractors. Here we show that when the full advection dynamics is considered, including the history force, both the nature and the number of attractors change, and a fractalization of their basins of attraction appears. In particular, we show that the history force significantly weakens the horizontal diffusion and changes the speed of sedimentation or rising. The influence of the history force is dependent on the size of the advected particles, being stronger for larger particles.