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Bounds to the Basset-Boussinesq force on particle laden stratified flows
Building: Cero Infinito
Room: 1403
Date: 2024-12-13 03:00 PM – 03:20 PM
Last modified: 2024-11-25
Abstract
The Maxey-Riley equation, which governs the motion of small inertial particles in turbulent flows, is a prominent example of a dynamical system with infinite degrees of freedom. This arises due to the inclusion of the Basset-Boussinesq history force, which transforms the equations into integro-differential form by incorporating the particles' past velocities. While this force is often neglected for convenience, it is of the same order as other viscous forces, raising questions about the validity of its exclusion. In this study, we focus on the conditions under which the Basset-Boussinesq force can be safely neglected, particularly for light particles in geophysical turbulent flows. By deriving strict bounds based on the buoyancy Stokes number $\textrm{Sb} = N \tau_p$, where $N$ is the Brunt-Väisälä frequency and $\tau_p$ is the particle's Stokes time, we show that for many oceanic conditions, this force can indeed be negligible. However, in strongly stratified environments or for particles with significant inertia, it plays a critical role in the dynamics. Our results, validated through direct numerical simulations, provide new insights into the intricate dynamics of particle-laden geophysical flows and contribute to a deeper understanding of the limits of simplified models in such systems.