@article {633,
	title = {Two-dimensional numerical simulation of chimney fluidization in a granular medium using a combination of discrete element and lattice Boltzmann methods},
	journal = {Physical Review E},
	volume = {97},
	year = {2018},
	month = {May-10-2018},
	pages = { Article Number 052902 },
	abstract = {<p>We present here a numerical study dedicated to the fluidization of a submerged granular medium induced by a localized fluid injection. To this end, a two-dimensional (2D) model is used, coupling the lattice Boltzmann method (LBM) with the discrete element method (DEM) for a relevant description of fluid-grains interaction. An extensive investigation has been carried out to analyze the respective influences of the different parameters of our configuration, both geometrical (bed height, grain diameter, injection width) and physical (fluid viscosity, buoyancy). Compared to previous experimental works, the same qualitative features are recovered as regards the general phenomenology including transitory phase, stationary states, and hysteretic behavior. We also present quantitative findings about transient fluidization, for which several dimensionless quantities and scaling laws are proposed, and about the influence of the injection width, from localized to homogeneous fluidization. Finally, the impact of the present 2D geometry is discussed, by comparison to the real three-dimensional (3D) experiments, as well as the crucial role of the prevailing hydrodynamic regime within the expanding cavity, quantified through a cavity Reynolds number, that can presumably explain some substantial differences observed regarding upward expansion process of the fluidized zone when the fluid viscosity is changed.</p>
},
	issn = {2470-0045},
	doi = {10.1103/PhysRevE.97.052902},
	url = {https://link.aps.org/doi/10.1103/PhysRevE.97.052902},
	author = {Jeff Ngoma and Pierre Philippe and St{\'e}phane Bonelli and Farhang Radja{\"\i} and Jean-Yves Delenne}
}
@proceedings {359,
	title = {Transient regime to fluidized chimney within a granular bed by means of a 2D DEM/LBM modeling},
	journal = {IV International Conference on Particle-based Methods (PARTICLES 2015)},
	volume = {PARTICLE-BASED METHODS IV-FUNDAMENTALS AND APPLICATIONS},
	year = {2015},
	month = {sept-30-2015},
	pages = {558-566},
	publisher = {International Center for Numerical Methods in Engineering (CIMNE)},
	address = {SEP 28-30 2015 Barcelona, SPAIN},
	abstract = {<p>Beyond a given threshold, an upward fluid flow at constant flowrate, injected through a small size section, is able to generate a fluidization along a vertical chimney over the entire height of a granular assembly. Fluidization is first initiated in the immediate vicinity of the injection hole and then the fluidized zone grows gradually until reaching the upper surface of the granular packing. In this work, we present numerical results on the kinetics of chimney fluidization in an immersed granular bed produced with two-dimensional simulations coupling the Discrete Element and Lattice Boltzmann Methods (DEM-LBM). A parametric study is carried out with 11 different sets of physical parameters and analyzed based on spatio-temporal diagrams. Then a dimensional analysis allows finding general scaling laws for both threshold and growth rate of the fluidized zone by use of two dimensionless numbers, namely Reynolds and Archimedes numbers, while quite simple empirical relationships can also be proposed.</p>
},
	keywords = {DEM, Fluidization, Granular Materials, LBM},
	url = {https://hal.archives-ouvertes.fr/hal-01269325},
	author = {Jeff Ngoma and Pierre Philippe and St{\'e}phane Bonelli and Cuellar, Pablo and Jean-Yves Delenne and Farhang Radja{\"\i}},
	editor = {Onate, E and Bischoff, M and Owen, DRJ}
}
