Inertial particles move differently from the suspending flow due to finite-time hydrodynamic response to perturbations. While viscosity-dominated Stokes flows are well-studied under steady conditions, their unsteady route to the steady state is not. We examine particle transport using the unsteady Stokes model, capturing the non-instantaneous relaxation.
We revisit the classical problem of a settling sphere in the unsteady Stokes model to highlight emergence of memory effects, and include comparisons with experiments. To address the computational challenges of memory effects in general flows, we develop a memoryless framework which leads to an explicit integrator to solve the Maxey-Riley-Gatignol (MRG) equation. We show how the approach may be generalized to other nonlocal evolutionary equations.
We numerically investigate memory effects on non-interacting particles in rotating vortical flows. Finally, we describe a 2D multi-particle model with fluid-mediated interactions in the unsteady Stokes regime, setting the framework for future development of an MRG analogue that includes interactions.
Zoom link: https://icts-res-in.zoom.us/j/92198823133?pwd=aPecflW5tNFs0FXTWA5EHMy2kDgfyJ.1
Meeting ID: 921 9882 3133
Passcode: 242425