Morphological transitions in partially gas-fluidized granular mixtures

Nermoen, Anders; Raufaste, Christophe; deVilliers, Simon Daniel; Jettestuen, Espen; Meakin, Paul; Dysthe, Dag Kristian

doi:10.1103/physreve.81.061305

Cited by 12 publications

(9 citation statements)

References 110 publications

(158 reference statements)

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“…Walters et al 2006). Gernon et al (2009), andNermoen et al (2010b) studied the complex fluidization processes of mixtures of fine-grained and coarse-grained granular Fig. 23 Characteristic experimental studies of magma-fault interactions in various tectonic settings.…”

Section: Explosive Volcanic Ventsmentioning

confidence: 99%

Laboratory Modelling of Volcano Plumbing Systems: A Review

Galland

Holohan

Vries

et al. 2015

Advances in Volcanology

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We review the numerous experimental studies dedicated to unravelling the physics and dynamics of various parts of a volcanic plumbing system. Section 1 lists the model materials commonly used for model magmas or model rocks. We describe these materials' mechanical properties and discuss their suitability for modelling sub-volcanic processes. Section 2 examines the fundamental concepts of dimensional analysis and similarity in laboratory modelling. We provide a step-by-step explanation of how to apply dimensional analysis to laboratory models in order to identify fundamental physical laws that govern the modelled processes in dimensionless (i.e. scale independent) form. Section 3 summarises and discusses the past applications of laboratory models to understand numerous features of volcanic plumbing systems. These include: dykes, cone sheets, sills, laccoliths, caldera-related structures, ground deformation, magma/fault interactions, and explosive vents. We outline how laboratory models have yielded insights into the main geometric and mechanical controls on the development of each part of the volcanic

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Section: Explosive Volcanic Ventsmentioning

confidence: 99%

Laboratory Modelling of Volcano Plumbing Systems: A Review

Galland

Holohan

Vries

et al. 2015

Advances in Volcanology

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“…Concerning, in particular, the injection of a gas in granular materials, we can distinguish the biphasic case (grains and air) [23] from the triphasic case (grains, fluid, and air) [24,25], the latter being more complex and not fully understood. The dynamics of the interface between air and an immersed granular material has been experimentally studied in a Hele-Shaw cell [26], mainly in a regime in which the gas forms a finger, reminiscent of the Saffman-Taylor finger.…”

Section: Introductionmentioning

confidence: 99%

Morphology of air invasion in an immersed granular layer

2011

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We report a study of the paths formed by a finite volume of air gently injected at the base of an immersed granular material. A two-dimensional model, based on experimental observations, shows that the typical height and width of the region explored by the branched path depends not only on the injected volume V, but also on a dimensionless parameter χ which accounts for the relative effects of the gravity and capillarity. For a given injected volume V, larger gravity effects lead to taller and narrower structures; for a given χ, the typical height and width of the structure scale like V(1/2) and V(1/4), respectively, while the typical gaseous fraction in the corresponding region increases accordingly like V(1/4). Such results can be of practical importance: For instance, gas can be trapped on purpose in an underground natural container below a granular slurry. Our results can help in predicting if the gas is likely to reach the free surface and escape the system if the container presents a defect (hole or fracture).

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“…Many studies have been performed in two-phase systems to analyze the mechanisms at play in the fluid venting process, either for dry (gas/grains) [25,26] or wet (liquid/grains) [16,22,27,28] beds. For unconstrained beds, where the grains are likely to move and their free surface to deform, different patterns have been thoroughly described when changing the fluid injection flow-rate, Q, in the granular matrix.…”

Section: Introductionmentioning

confidence: 99%

Flow and fracture in water-saturated, unconstrained granular beds

et al. 2015

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The injection of gas in a liquid-saturated granular bed gives rise to a wide variety of invasion patterns. Many studies have focused on constrained porous media, in which the grains are fixed in the bed and only the interstitial fluid flows when the gas invades the system. With a free upper boundary, however, the grains can be entrained by the ascending gas or fluid motion, and the competition between the upward motion of grains and sedimentation leads to new patterns. We propose a brief review of the experimental investigation of the dynamics of air rising through a water-saturated, unconstrained granular bed, in both two and three dimensions. After describing the invasion pattern at short and long time, a tentative regime-diagram is proposed. We report original results showing a dependence of the fluidized zone shape, at long times, on the injection flow rate and grain size. A method based on image analysis makes it possible to detect not only the fluidized zone profile in the stationary regime, but also to follow the transient dynamics of its formation. Finally, we describe the degassing dynamics inside the fluidized zone, in the stationary regime. Depending on the experimental conditions, regular bubbling, continuous degassing, intermittent regime or even spontaneous flow-to-fracture transition are observed.

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Morphological transitions in partially gas-fluidized granular mixtures

Cited by 12 publications

References 110 publications

Laboratory Modelling of Volcano Plumbing Systems: A Review

Laboratory Modelling of Volcano Plumbing Systems: A Review

Morphology of air invasion in an immersed granular layer

Flow and fracture in water-saturated, unconstrained granular beds

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