Lattice Boltzmann simulations of low-Reynolds-number flow past fluidized spheres: Effect of Stokes number on drag force

Gregory J. Rubinstein, J. J. Derksen, Sankaran Sundaresan

Research output: Contribution to journalArticle

40 Scopus citations

Abstract

In a fluidized bed, the drag force acts to oppose the downward force of gravity on a particle, and thus provides the main mechanism for fluidization. Drag models that are employed in large-scale simulations of fluidized beds are typically based on either fixed-particle beds or the sedimentation of particles in liquids. In low-Reynolds-number (Re) systems, these two types of fluidized beds represent the limits of high Stokes number (St) and low St, respectively. In this work, the fluid-particle drag behaviour of these two regimes is bridged by investigating the effect of St on the drag force in low-Re systems. This study is conducted using fully resolved lattice Boltzmann simulations of a system composed of fluid and monodisperse spherical particles. In these simulations, the particles are free to translate and rotate based on the effects of the surrounding fluid. Through this work, three distinct regimes in the characteristics of the fluid-particle drag force are observed: low, intermediate and high St. It is found that, in the low-Re regime, a decrease in St results in a reduction in the fluid-particle drag. Based on the simulation results, a new drag relation is proposed, which is, unlike previous models, dependent on St.

Original languageEnglish (US)
Pages (from-to)576-601
Number of pages26
JournalJournal of Fluid Mechanics
Volume788
DOIs
StatePublished - Jan 8 2016

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Keywords

  • fluidized beds
  • particle/fluid flow
  • suspensions

Fingerprint Dive into the research topics of 'Lattice Boltzmann simulations of low-Reynolds-number flow past fluidized spheres: Effect of Stokes number on drag force'. Together they form a unique fingerprint.

Cite this