Revisiting the Homogenized Lattice Boltzmann Method with Applications on Particulate Flows

Robin Trunk,Timo Weckerle,Hermann Nirschl,Nicolas Hafen,Mathias J. Krause,Gudrun Thäter

doi:10.3390/computation9020011

Abstract

The simulation of surface resolved particles is a valuable tool to gain more insights in the behaviour of particulate flows in engineering processes. In this work the homogenized lattice Boltzmann method as one approach for such direct numerical simulations is revisited and validated for different scenarios. Those include a 3D case of a settling sphere for various Reynolds numbers. On the basis of this dynamic case, different algorithms for the calculation of the momentum exchange between fluid and particle are evaluated along with different forcing schemes. The result is an updated version of the method, which is in good agreement with the benchmark values based on simulations and experiments. The method is then applied for the investigation of the tubular pinch effect discovered by Segré and Silberberg and the simulation of hindered settling. For the latter, the computational domain is equipped with periodic boundaries for both fluid and particles. The results are compared to the model by Richardson and Zaki and are found to be in good agreement. As no explicit contact treatment is applied, this leads to the assumption of sufficient momentum transfer between particles via the surrounding fluid. The implementations are based on the open-source C++ lattice Boltzmann library OpenLB.

Highlights

The simulation of particulate flows finds application in many fields as it permits a detailed examination of an engineering process
This setup was used to examine the settling for different Reynolds numbers by varying the fluid density ρf and dynamic viscosity μf
MEA-L and MEA-W refer to the momentum exchange algorithms by Ladd [39,40] and Wen et al [42]

Summary

Introduction

The simulation of particulate flows finds application in many fields as it permits a detailed examination of an engineering process. It allows access to data on particle behaviour, for which experimental measuring is complex or costly. It was already applied for the simulation of solid separation processes by Viduka et al [1], testing different pulsation profiles of a jigging device, or by Li et al [2] regarding the separation of soybeans from mustard seeds. The industrial relevance of this topic has been shown, e.g., by Champion et al [3] who showed that particle shape significantly influences the performance of drug carriers. A discussion on the industrial relevance of particle shape for products and processes is given by Davies [4], who references, e.g., the relevance for the production of rubber, as stated by Scotti et al [5]

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Discussion

Conclusion