Palabos Turret: A Particle-Resolved Numerical Framework for Settling Dynamics of Arbitrary-Shaped Particles

TL;DR

The paper introduces Palabos Turret, a novel 3D numerical framework that simulates the settling behavior of arbitrarily shaped particles in fluids across a wide range of Reynolds numbers, with high accuracy.

Contribution

It presents a new particle-resolved simulation method combining lattice Boltzmann, immersed boundary, and recursive collision models for arbitrary-shaped particles.

Findings

Validated against experimental and analytical data with high accuracy.

Accurately simulates translational and rotational dynamics of complex particles.

Works across a broad Reynolds number range from 0.5 to 40,000.

Abstract

Particles transported in fluids are everywhere, occurring for example in indoor air, the atmosphere, the oceans, and engineering applications. In this study, a novel three-dimensional numerical framework -- the Palabos Turret is presented, which allows fully resolved simulations of the settling dynamics of heavy particles with arbitrary shapes over a wide range of particle Reynolds numbers. The numerical solver is based on the lattice Boltzmann method utilizing immersed-boundary approach and a recursive-regularized collision model to fully resolve the particle-fluid interactions. A predictor-corrector scheme is applied for the robust time integration of the six-degrees-of-freedom (6DOF) rigid-body motion. Finally, the multi-scale nature arising from the long free-fall distances of a particle is addressed through a dynamic memory allocation scheme allowing for a virtually infinite falling distance. This solver allows for the simulation of particles of any arbitrary shape. The proposed framework is validated using the analytical and experimental data of freely-falling spheres, ellipsoids, and an irregular particle in a wide range of Reynolds numbers between $5\times10^{-1}$ and $4\times10^4$. For different Reynolds numbers and particle shapes considered, the Palabos Turret shows excellent agreement compared to theoretical and experimental values with a median relative deviation of $\pm1.5\%$ and a maximum deviation of $\pm5\%$. The Palabos Turret enables an in-depth analysis of the translational and rotational dynamics of particles with complex geometries.