Destabilization of Immersed Dense Granular Material Submitted to Localized Fluidization: An Experimental and Numerical Study

Aboubacar Sidiki Dramé,Li Wang,Yanping Zhang,Jeongkwon Kim

doi:10.1155/2021/5542835

Abstract

An alternative experimental approach and a numerical analysis for the study of destabilization by localized fluidization of an immersed dense granular material are presented. To visualize the evolutions of the internal structure of the granular medium, the hydrogel beads, composed of about 99% of water and having substantially the same refraction indexes, are used as solid phase. A LED lighting system is used in place of a laser lighting system. As a result, the optical access restriction of porous structure is removed. A real economic alternative for the experimental study of fluid-grain coupling during destabilization by localized fluidization of a granular material is created. The experimental phenomenology presented in the literature is verified: the system passes successively through three different stationary regimes: static regime, fluidized cavity regime, and fluidized chimney regime. Some restrictions of using hydrogel beads as particles in the study of liquid-solid interaction are also discussed.

Highlights

Fluidization consists of the setting in movement of a package of particles under the effect of a fluid flow
We can single out the experimental works, by Zoueshthiagh and Merlen [1] and Philippe and Badiane [2], and some numerical works, including for Cui et al, Marzougui et al, Jeff Ngoma et al, Montell et al and Rigord et al [3,4,5,6,7]. e study of the destabilization by localized fluidization of a granular material as well as the study of the behavior of the flows in porous media necessitated a wide use of several optical techniques: the iso-index technique and the laser-induced fluorescence (PLIF), the laser Doppler velocimetry (LDA), the particle tracking velocimetry (PTV), and the particle image velocimetry (PIV) have been extensively used [2, 8,9,10]. ese investigation methods strongly depend on the quality of the refractive index adequacy of the solid and liquid phases [11, 12]
Many researchers have reported that, in order to visualize the evolutions of the internal structure of the granular medium without having recourse to a two-dimensional geometry, the interstitial fluid must be adapted to examples of mixtures of silicon oil, glycerol, or any other mineral oil [9, 10]

Summary

Introduction

Fluidization consists of the setting in movement of a package of particles under the effect of a fluid flow. Several techniques have been used in the past for the experimental and numerical study of the hydrodynamic coupling between the phases present in the fluidization. E study of the destabilization by localized fluidization of a granular material as well as the study of the behavior of the flows in porous media necessitated a wide use of several optical techniques: the iso-index technique and the laser-induced fluorescence (PLIF), the laser Doppler velocimetry (LDA), the particle tracking velocimetry (PTV), and the particle image velocimetry (PIV) have been extensively used [2, 8,9,10]. In the ultimate concern to visualize the movement of particles of the granular structure inside the porous medium, Philippe and Badiane used the iso-index technique and laser-induced

Methods

Results

Conclusion