Discrete particle modeling of granular Rayleigh–Taylor instability

Yu, Zhiyi; Wu, Chunliang; Berrouk, Abdallah S.; Nandakumar, K.

doi:10.1016/j.ijmultiphaseflow.2015.08.010

Cited by 8 publications

(7 citation statements)

References 26 publications

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“…The height of the domain (in y) is chosen such that the confinement of the top and boundary boundaries has negligible effects on the interfacial instabilities according to the linear theory 24 . The domain thickness (in z) is six times the particle diameter, which is comparable to a recent numerical study 13 . The top and bottom boundaries (i.e., y = 0 or 15 mm) are no-slip and non-penetrable.…”

Section: B Simulation Configurationsupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

“…The granular RTI have also been studied numerically [7][8][9][10][11][12][13][14] . Some of these simulations involved a discrete description of the granular particles [7][8][9][10][13][14][15] , while others treated the granular suspension as a continuous fluid phase 11,12 . In their two-dimensional (2D) direct numerical simulations, Pan et al 10 varied the initial solid fraction (φ 0 ) and observed regularly spaced perturbations at the interface.…”

Section: Introductionmentioning

confidence: 99%

“…Yet, the numerical results agreed with their experimental counterpart in terms of the time evolution of wave number, k. The same numerical method was extended by Niebling et al 9,15 to investigate the effects of fluid compressibility and viscosity. Yu et al 13 performed three-dimensional (3D) simulations which solved Navier-Stokes equations for the fluid phase and applied Newton's Second Law to discrete particle dynamics; momentum exchange between the fluid and particles was modelled by empirical drag laws. The authors varied φ 0 from 0.41 to 0.60, and the results agreed well with experiments 7 in terms of k. In their Euler-Lagrange computational framework, Chou et al 14,16 modelled the particle-fluid momentum exchange by parameterizing the particle relaxation time.…”

Section: Introductionmentioning

confidence: 99%

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Evolution of Rayleigh−Taylor instability at the interface between a granular suspension and a clear fluid

2022

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We report the characteristics of Rayleigh-Taylor instabilities (RTI) occurring at the interface between a suspension of granular particles and a clear fluid. The time evolution of these instabilities is studied numerically using coupled lattice Boltzmann and discrete element methods with a focus on the overall growth rate (σ) of the instabilities and their average wave number (k). Special attention is paid to the effects of two parameters, the solid fraction (0.10{less than or equal to}φ{less than or equal to}0.40) of the granular suspension and the solid-to-fluid density ratio (1.5{less than or equal to}R{less than or equal to}2.7). Perturbations at the interface are observed to undergo a period of linear growth, the duration of which decreases with φ and scales with the particle shear time d/w∞, where d is the particle diameter and w∞ is the terminal velocity. For φ>0.10, the transition from linear to nonlinear growth occurs when the characteristic steepness of the perturbations is around 29%. At this transition, the average wave number is approximately 0.67d-1 for φ>0.10 and appears independent of R. For a given φ, the growth rate is found to be inversely proportional to the particle shear time, i.e., σ ∝(d/w∞)-1; at a given R, σ increases monotonically with φ, largely consistent with a linear stability analysis (LSA) in which the granular suspension is approximated as a continuum. These results reveal the relevance of the time scale d/w∞ to the evolution of interfacial granular RTI, highlight the various effects of φ and R on these instabilities, and demonstrate modest applicability of the continuum-based LSA for the particle-laden problem.

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Section: B Simulation Configurationsupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Evolution of Rayleigh−Taylor instability at the interface between a granular suspension and a clear fluid

2022

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“…e capability and use of the CFD-DEM combination have been reported recently in the literature for a wide range of applications, including fluidized beds [14][15][16][17][18][19], filtration processes [20][21][22][23][24], hole cleaning and sediment transport in the oil and gas industry [25][26][27][28], hydrocyclones, vortex flow, and instabilities [29][30][31], and bed-load transport [32,33]. Specifics of the CFD-DEM coupling have also been documented, including studies of different types of DEM coupling [34], numerical errors involved in the models [35], requirements for the coupling with distinct fluid mechanics numerical models [36][37][38], and the use of nonspherical particles [39].…”

Section: Introductionmentioning

confidence: 99%

Numerical Evaluation of CFD‐DEM Coupling Applied to Lost Circulation Control: Effects of Particle and Flow Inertia

Barbosa

Lai

Junqueira

2019

Mathematical Problems in Engineering

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In the present study, the transport and deposition of solid particles to mitigate the loss circulation of fluid through a fracture transversely placed to a vertical channel is numerically investigated. These solid particles (commonly known in the industry as lost circulation materials—LCMs) are injected into the flow during the drilling operation in the petroleum industry, in hopes to control the fluid loss. The numerical simulation of the process follows a two-stage process: the first characterizes the lost circulation flow and the second the particle injection. The numerical model comprises an Eulerian–Lagrangian approach, in which the dense discrete phase model (DDPM) is combined with the discrete element method (DEM). A parametric analysis is done by varying the vertical channel Reynolds number, the particle-to-fluid density ratio, and the particle diameter. Results are shown in terms of the particle’s bed geometric characteristics, focusing on the location inside the fracture where the particles deposit, and the particle bed length, height, and time spent to fill the fracture. Also monitored are the fluid loss reduction over time and the fractured channel bottom pressure (which can be related to the fracture pressure). Results indicate that using a slow/intermediate flow velocity, associated with heavy particles with small diameters, provides the best combination for the efficient mitigation of the fluid loss process.

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Controlling the Flow Structure in Fluidized Bed: A CFD-DEM Approach

Oliveira

Ayeni

et al. 2016

Springer Proceedings in Physics

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Discrete particle modeling of granular Rayleigh–Taylor instability

Cited by 8 publications

References 26 publications

Evolution of Rayleigh−Taylor instability at the interface between a granular suspension and a clear fluid

Evolution of Rayleigh−Taylor instability at the interface between a granular suspension and a clear fluid

Numerical Evaluation of CFD‐DEM Coupling Applied to Lost Circulation Control: Effects of Particle and Flow Inertia

Controlling the Flow Structure in Fluidized Bed: A CFD-DEM Approach

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