Eulerian-Lagrangian Two Phase Debris Flow Model

Franklin, Martínez; Cora, E

doi:10.25148/etd.fi09121601

Cited by 4 publications

(9 citation statements)

References 45 publications

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“…The lowest value of μ B is chosen to be close to our 18% slurry; in our experiments the 17% mudflow runs out of the depositional plain. The parameter space is considered to be realistic because it encompasses the characteristics of several kinds of slurries, including the one used in our experiments (Table ) and those reported in the literature (Coussot, ; Kaitna et al, ; Martinez, ). Note that the initial volume ( V = 3 L) and slope angle ( θ = 14 ∘ ) remain unaltered in these cases.…”

Section: Experimental and Numerical Resultsmentioning

confidence: 99%

“…However, in the fast propagation and deposition of mudflows, where the inertia effect becomes relevant, the relative role of viscosity and yield stress remains unclear, especially with an inclined flow configuration. Moreover, event‐specific variation of rheological characteristics may result in different deposit morphologies observed in both natural mudflows and laboratory experiments (Ancey & Cochard, ; Balmforth et al, ; Cochard & Ancey, ; Hürlimann et al, ; Martinez, ; Parsons et al, ). Some experimental deposits with a similar flume geometry are given in Figures b–e, where clearly different deposit shapes are observed (e.g., semicircular, hill shaped, and elongated) for a variety of materials.…”

Section: Introductionmentioning

confidence: 99%

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Runout Scaling and Deposit Morphology of Rapid Mudflows

et al. 2018

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Prediction of runout distance and deposit morphology is of great importance in hazard mitigation of geophysical flows, including viscoplastic mudflows. The major rheological parameters of mudflows, namely, yield stress and viscosity, are crucial factors in controlling the runout and deposition processes. However, the roles of the two parameters, especially in mudflows with high inertia, remain poorly understood and are not accounted for in runout scaling relations with source volume. Here we investigate the effects of flow rheology on runout scaling and deposit morphology using small‐scale laboratory experiments and three‐dimensional numerical simulations. We find that yield stress and viscosity both influence flow velocity gained during downslope propagation of mudflows, which is strongly correlated with the runout distance; the role of yield stress is more significant than viscosity. High yield stress and low viscosity lead to an elongated deposit, where longitudinal propagation is more significant than lateral spreading. In contrast, high viscosity promotes the dominance of lateral spreading of the deposit, while low yield stress and moderate viscosity produce an initial elongate deposit, followed by a secondary surge that spreads laterally near the head of the deposit. Following appropriate scaling relations for viscosity and yield stress, a general scaling function is proposed to incorporate flow properties in the well‐known correlation of runout distance and source volume. Our findings regarding the inertia effects and the roles of yield stress and viscosity enhance our understanding of mudflows, muddy debris flows, and other viscoplastic geophysical flows.

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Section: Experimental and Numerical Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Runout Scaling and Deposit Morphology of Rapid Mudflows

et al. 2018

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“…The equations of formation, mass continuity and momentum of a debris flow can be integrated with depth. In a fixed Cartesian coordinate system (x, y, z) with z pointing up against the direction of gravity, the formation equation can be reduced to the average depth relationship in the x-y plane [5]. The finite element method is one of the numerical solutions to obtain an approximate solution to a physical problem [6].…”

Section: Literature Reviewmentioning

confidence: 99%

An Alternative Algorithm for Simulating Flash Flood

Khaldirian

Rahardjo

Luknanto

et al. 2021

IOP Conf. Ser.: Earth Environ. Sci.

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Most of the approaches in numerical modeling techniques are based on the Eulerian coordinate system. This approach faces difficulty in simulating flash flood front propagation. This paper shows an alternative method that implements a numerical modeling technique based on the Lagrangian coordinate system to simulate the water of debris flow. As for the interaction with the riverbed, the simulation uses an Eulerian coordinate system. The method uses the conservative and momentum equations of water and sediment mixture in the Lagrangian form. Source terms represent deposition and erosion. The riverbed in the Eulerian coordinate system interacts with the flow of the mixture. At every step, the algorithm evaluates the relative position of moving nodes of the flow part to the fixed nodes of the riverbed. Computation of advancing velocity and depth uses the riverbed elevation, slope data, and the bed elevation change computation uses the erosion or deposition data of the flow on the moving nodes. Spatial discretization is implementing the Galerkin method. Furthermore, temporal discretization is implementing the forward difference scheme. Test runs show that the algorithm can simulate downward, upward, and reflected backward 1-D flow cases. Two-D model tests and comparisons with SIMLAR software show that the algorithm works in simulating debris flow.

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“…Although several models are theoretically equipped with the capability of determining the velocity differences, they are too complex to be solved and validated by the experimental dataset (Martinez, 2009). In addition, most of these two-phase models can only be applied under very strict parametric conditions, which is quite far away from the practical purpose (Martinez, 2009).…”

Section: Introductionmentioning

confidence: 99%

“…In addition, most of these two-phase models can only be applied under very strict parametric conditions, which is quite far away from the practical purpose (Martinez, 2009). The above-mentioned limitations mean that the transport and deposition dynamics of non-homogeneous debris flows are still poorly understood, especially the relative behaviour of (and the interactions between) fluid and solid phases, as well as how this is influenced by the composition and bulk density of the debris flows.…”

Section: Introductionmentioning

confidence: 99%

Study on two-phase dynamic behaviours within non-homogeneous debris flow

Shu

Wang

Shao

et al. 2018

Proceedings of the Institution of Civil Engineers - Water Manag

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The non-homogeneous debris flows, consisting of a wide range of grain size, bulk density and demonstrating non-uniform velocity distributions, are commonly modeled as the two-phase flow. In adopting such an approach, a critical grain diameter to separate the solid and liquid phase, within such debris flows, can be determined through the principles of minimum energy dissipation. In the current study, an improved analytical approach using the resistance formula of water flow and mass conservation law is presented to determine the velocity of the solid and liquid phases within a non-homogeneous debris flow, based on the derived critical grain diameter. Some of the dynamic parameters required in the analysis are validated against the experimental data of a non-homogeneous, two-phase debris flow measured from the Jiangjia gully, Yunnan Province of China. The results show that, for the majority of non-homogeneous debris flows tested, the liquid phase exhibits higher velocity than the solid phase. However, as the bulk density of the debris flow increases, the solid phase tends to have higher velocity than the liquid phase. These findings are shown to have important implications on the vertical grading patterns of the bed deposits in depositional areas. The observations from the field studies indicate that the non-homogeneous debris flows with bulk density being significantly lower, close to and significantly higher than the critical value seem to exhibit normal (i.e. bed-to-surface vertical fining), mixed, and inverse (bed-to-surface vertical coarsening) grading patterns in the alluvial fan deposits.

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Eulerian-Lagrangian Two Phase Debris Flow Model

Cited by 4 publications

References 45 publications

Runout Scaling and Deposit Morphology of Rapid Mudflows

Runout Scaling and Deposit Morphology of Rapid Mudflows

An Alternative Algorithm for Simulating Flash Flood

Study on two-phase dynamic behaviours within non-homogeneous debris flow

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