From model conception to verification and validation, a global approach to multiphase Navier-Stoke models with an emphasis on volcanic explosive phenomenology

Dartevelle, Sebastian

doi:10.2172/948564

Cited by 6 publications

(10 citation statements)

References 34 publications

(87 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The underexpanded jet analog validation test cases demonstrate the adequacy and the accuracy of GMFIX to capture single to multiphase dynamics under supersonic and shocked conditions. GMFIX accurately captures the shock disc positions, even with coarser grid resolutions [ Dartevelle , 2007]. These tests also demonstrate the adequacy of the model for coupling between particles and gas phase through shocks.…”

Section: Model Validationmentioning

confidence: 88%

“…Section 6.2 summarizes a comparison of GMFIX model calculations with the 1977 eruption of tephra through a geothermal wellbore in Iceland that was intersected by a dike at a depth of ∼1 km, which is the only example of basaltic magma interacting with a man‐made opening that we are aware of. Both of these validation studies are reported in detail elsewhere (see Dartevelle [2007] and Dartevelle and Valentine [2007a], respectively).…”

Section: Model Validationmentioning

confidence: 99%

“…GMFIX (v1.62) is the code implementation of the conceptual multiphase Navier‐Stokes model of Dartevelle [2005] and the multiphase turbulence model of Simonin [1996] [see also Benyahia et al , 2005]. The numerical implementation of Dartevelle 's [2005] conceptual models into the GMFIX code has been extensively tested to ensure that the results of simulations are accurate representations of the physical systems modeled [ Dartevelle , 2007]. First, the GMFIX code has been verified against ideal and analytical Riemann's shock tube test cases.…”

Section: Model Validationmentioning

confidence: 99%

“…First, the GMFIX code has been verified against ideal and analytical Riemann's shock tube test cases. Dartevelle [2007] showed that the numerical solvers and the spatial and time discretization methods implemented in GMFIX ensure the accuracy of the numerical solutions. In addition, it was shown that the numerical accuracy is independent on the grid size chosen even though, as expected, the quality of the numerical results decreases with coarser grid size.…”

Section: Model Validationmentioning

confidence: 99%

“…This coupled multiphase turbulence model merges together the classical Reynolds‐averaged Navier‐Stokes approach [ Benyahia et al , 2005] of gas turbulence with a kinetic‐collisional‐plastic model for the dispersed phase [ Dartevelle , 2004]. Given the experimental errors, the numerical results (speed and kinetic turbulent energies) were generally good when compared with analog results, although Dartevelle [2007] showed that some of the observed discrepancies in the turbulent kinetic energy profiles could be improved in generalizing the turbulent model to a full four‐scalar partial differential equation RANS model.…”

Section: Model Validationmentioning

confidence: 99%

See 4 more Smart Citations

Multiphase magmatic flows at Yucca Mountain, Nevada

Dartevelle¹,

Valentine²

2008

J. Geophys. Res.

View full text Add to dashboard Cite

[1] The proposed Yucca Mountain radioactive waste repository is sited in southern Nevada in a region that has experienced sporadic basaltic volcanism since the late Miocene. Volcanic risk assessment for the proposed repository requires estimating the consequences of a new monogenetic volcano intersecting the underground facility during its 10 4 -10 6 year performance period. We report numerical studies aimed at understanding the range of processes and dynamic parameter values that could accompany intersection of an open repository drift by a volatile-rich trachybasaltic magma as it ascends in a dike. We focus on one end-member type of magmatic behavior, namely, a fragmented magmatic mixture under pressure interacting with an underground cavity. Initial and boundary conditions are based upon field data and previous modeling studies of the interaction between vertically propagating dikes and a repository opening. The calculations are two-dimensional and time-dependent and are conducted with the multiphase hydrodynamics code GMFIX. Calculations indicate that gas-particle mixtures, as they rise from below and interact with horizontal openings, form complex flow patterns involving varying degrees of recirculation and deposition of pyroclasts. Dynamic pressures are up to 10 6 Pa but are more typically on the order of 10 3 to 10 4 Pa. The geometry and number of outlets play a key role in determining the types of flow patterns, as do volatile contents and the degree of fragmentation. The detailed numerical simulations provide information that will be used to confirm the adequacy of simplified probabilistic consequence models used in risk assessments.

show abstract

Section: Model Validationmentioning

confidence: 88%

Section: Model Validationmentioning

confidence: 99%

Section: Model Validationmentioning

confidence: 99%

Section: Model Validationmentioning

confidence: 99%

Section: Model Validationmentioning

confidence: 99%

See 3 more Smart Citations

Multiphase magmatic flows at Yucca Mountain, Nevada

Dartevelle¹,

Valentine²

2008

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

Compressible Flow Phenomena at Inception of Lateral Density Currents Fed by Collapsing Gas‐Particle Mixtures

Valentine

Sweeney

2018

JGR Solid Earth

View full text Add to dashboard Cite

Many geological flows are sourced by falling gas‐particle mixtures, such as during collapse of lava domes, and impulsive eruptive jets, and sustained columns, and rock falls. The transition from vertical to lateral flow is complex due to the range of coupling between particles of different sizes and densities and the carrier gas, and due to the potential for compressible flow phenomena. We use multiphase modeling to explore these dynamics. In mixtures with small particles, and with subsonic speeds, particles follow the gas such that outgoing lateral flows have similar particle concentration and speed as the vertical flows. Large particles concentrate immediately upon impact and move laterally away as granular flows overridden by a high‐speed jet of expelled gas. When a falling flow is supersonic, a bow shock develops above the impact zone, and this produces a zone of high pressure from which lateral flows emerge as overpressured wall jets. The jets form complex structures as the mixtures expand and accelerate and then recompress through a recompression zone that mimics a Mach disk shock in ideal gas jets. In mixtures with moderate to high ratios of fine to coarse particles, the latter tend to follow fine particles through the expansion‐recompression flow fields because of particle‐particle drag. Expansion within the flow fields can lead to locally reduced gas pressure that could enhance substrate erosion in natural flows. The recompression zones form at distances, and have peak pressures, that are roughly proportional to the Mach numbers of impacting flows.

show abstract