A two-phase flow description of the initiation of underwater granular avalanches

Pailha, Mickaël; Pouliquen, Olivier

doi:10.1017/s0022112009007460

Cited by 151 publications

(260 citation statements)

References 42 publications

Supporting

Mentioning

249

Contrasting

Unclassified

Order By: Relevance

“…Going further than this qualitative argument and modeling the dynamics of granular collapse in a liquid remains a challenge, which needs to take into account the coupling between grains and liquid. The approach based on two-phase flow depth averaged equations developed 27 for the case of uniform avalanches could be a relevant framework.…”

Section: Discussionmentioning

confidence: 99%

“…The dynamics observed in this experiment can be captured theoretically using the framework of two phase flow equations. 27,28 The main goal of this paper is to study how the pore pressure feedback mechanism may affect the collapse of an immersed granular column. Our experiment consists in a dam-break configuration in a viscous liquid, in which we control the initial volume fraction of the column.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Granular collapse in a fluid: Role of the initial volume fraction

2011

View full text Add to dashboard Cite

The collapse of a granular column in a viscous liquid is experimentally investigated. The morphology of the deposits is shown to be mainly controlled by the initial volume fraction of the granular mass and not by the aspect ratio of the column, an observation which differs from dry granular collapse. Two different regimes are identified corresponding to initially loose and dense packings. Loose packings give rise to thin and long deposits, the dynamics being fast. A positive liquid pressure is measured below the column. For dense packings, the runout distance is twice less, the flow is slow, and a negative pore pressure is measured during the flow. These observations suggest that the dynamics of the granular collapse in a fluid is strongly affected by the dilatancy or contractancy behavior of the granular medium.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Granular collapse in a fluid: Role of the initial volume fraction

2011

View full text Add to dashboard Cite

show abstract

“…For this reason, mostly depthaveraged models have been proposed to deal with natural geophysical flows (e.g. [38], [36], [35], [10]). Iverson [15] was the first to address the need to include interstitial fluid effects in the constitutive behaviour of the mass flow and developed a thin layer model for a solid-fluid mixture moving on realistic terrain, under the simplifying assumptions of constant porosity and equality of the fluid and solid velocity.…”

Section: Introductionmentioning

confidence: 99%

“…A key issue in two-phase flow models is thus to propose a suitable closure relation that is compatible with the energy balance. Some new and very useful ways to close the system of equations have been proposed by Roux and Radjai [44], Pailha and Pouliquen [35] and George and Iverson [10]. The general idea is to take into account the dilation/compression of the granular phase and its interaction with the pressure of the fluid filling the pores of the granular material.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A two-phase shallow debris flow model with energy balance

et al. 2015

View full text Add to dashboard Cite

Abstract. This paper proposes a thin layer depth-averaged two-phase model provided by a dissipative energy balance to describe avalanches of solid-fluid mixtures. This model is derived from a 3D two-phase model based on the equations proposed by Jackson [R. Jackson, The Dynamics of Fluidized Particles, 2000] which takes into account the force of buoyancy and the forces of interaction between the solid and fluid phases. Jackson's model is based on mass and momentum conservation within the two phases, i.e. two vector and two scalar equations. This system has five unknowns: the solid volume fraction, the solid and fluid pressures and the solid and fluid velocities, i.e. three scalars and two vectors. As a result, an additional equation is necessary to close the system. Surprisingly, this issue is inadequately accounted for in the models that have been developed on the basis of Jackson's work. In particular, Pitman and Le [E.B. Pitman, L. Le, Phil. Trans. R. Soc. A, 2005] replaced this closure simply by imposing an extra boundary condition. If the pressure is assumed to be hydrostatic, this condition can be considered as a closure condition. However, the corresponding model cannot account for a dissipative energy balance. We propose here a closure equation to complete Jackson's model, imposing incompressibility of the solid phase. We prove that the resulting whole 3D model is compatible with a dissipative energy balance. From this model, we deduce a 2D depth-averaged model and we also prove that the energy balance associated with this model is dissipative. Finally, we propose a numerical scheme to approximate the depth-averaged model. We present several numerical tests for the 1D case that are compared to the results of the model proposed by Pitman and Le.1991 Mathematics Subject Classification. 65C20,81T80,91B74,97M10.The dates will be set by the publisher.

show abstract

Nonhydrostatic granular flow over 3-D terrain: New Boussinesq-type gravity waves?

Castro-Orgaz

Hutter

Giráldez

et al. 2015

J. Geophys. Res. Earth Surf.

View full text Add to dashboard Cite

Understanding granular mass flow is a basic step in the prediction and control of natural or man-made disasters related to avalanches on the Earth. Savage and Hutter (1989) pioneered the mathematical modeling of these geophysical flows introducing Saint-Venant-type mass and momentum depth-averaged hydrostatic equations using the continuum mechanics approach. However, Denlinger and Iverson (2004) found that vertical accelerations in granular mass flows are of the same order as the gravity acceleration, requiring the consideration of nonhydrostatic modeling of granular mass flows. Although free surface water flow simulations based on nonhydrostatic depth-averaged models are commonly used since the works of Boussinesq (1872, 1877), they have not yet been applied to the modeling of debris flow. Can granular mass flow be described by Boussinesq-type gravity waves? This is a fundamental question to which an answer is required, given the potential to expand the successful Boussinesq-type water theory to granular flow over 3-D terrain. This issue is explored in this work by generalizing the basic Boussinesq-type theory used in civil and coastal engineering for more than a century to an arbitrary granular mass flow using the continuum mechanics approach. Using simple test cases, it is demonstrated that the above question can be answered in the affirmative way, thereby opening a new framework for the physical and mathematical modeling of granular mass flow in geophysics, whereby the effect of vertical motion is mathematically included without the need of ad hoc assumptions.

show abstract

A two-phase flow description of the initiation of underwater granular avalanches

Cited by 151 publications

References 42 publications

Granular collapse in a fluid: Role of the initial volume fraction

Granular collapse in a fluid: Role of the initial volume fraction

A two-phase shallow debris flow model with energy balance

Nonhydrostatic granular flow over 3-D terrain: New Boussinesq-type gravity waves?

Contact Info

Product

Resources

About