Next year looks promising ! ]]>

Yanqing works on two major fronts: bubble dynamics in magma, studying the uptake of trace element during bubble growth for example. The second line of study deals with the effect of the pore-structure on the non-linear response of flow through a porous medium subjected to transient pore-pressure fluctuations.

Salah works on his multiphase flow experiments, characterizing the transport efficiency for a buoyant non-wetting fluid in a suspension versus in a porous medium. He also works on diffusion modeling in plagioclases with Caroline.

Andrea works on the development of a new multiphase flow lattice Boltzmann model (with Jonas Latt) and also the implementation of reactive pore-scale transport models with Babak. Andrea is also involved with the study of convection and mixing dynamics between different magmas in shallow reservoirs with Caroline.

Babak works on reactive transport at different scales. First studying the relevance of local equilibrium assumptions under different transport regimes and also working on the pore-scale reactive transport model with Andrea.

Caroline works on the Rabaul volcanic system in Papua New Guinea. She is working on diffusion modeling in olivines and plagioclases (using some new numerical tools developed in-house) to constrain timescales for the replenishment of the shallow reservoir. She is also working to understand the complex dynamics in the reservoir.

Wim works on developing a simplified model for the evolution of a shallow magma chamber subjected to recharge, cooling, visco-elastic relaxation, outgassing to study their effect on eruption frequency.

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Some ongoing projects include:

- Excess sulfur degassing during volcanic eruptions.
- Exsolved gas transport in magma chambers, accumulation of bubbles in shallow magma bodies.
- The effect of bubble-bubble interaction (deformation, competitive growth and coalescence) on eruption dynamics.
- Metal and other volatile favoring trace element partitioning and extraction out of magma bodies.
- Magma chamber dynamics, mixing dynamics for suspensions.

The study of complex physical processes involving multi-phase flows, pore-scale processes in porous media, reactive flow problems and diffusion in complex geometries requires the development of novel numerical models. Although we also use finite difference, finite volume or boundary integral methods, our main focus in term of numerical method is the lattice Boltzmann method (LB).

The lattice Boltzmann method is a kinetic theory based approach to solve partial differential equations. It is very successful for fluid dynamics in complex geometries, multiphase flows (especially for immiscible fluids) and flows with evolving solid-fluid boundaries. We have been developing new algorithms for

- imposing Dirichlet boundary conditions for the diffusion equation in complex geometries (Huber et al., IJMPC, 2011).
- multiphase flows, free surface flows, bubble dynamics (in prep).
- melting, dissolution processes coupled with fluid flow (Huber et al., 2008, Parmigiani et al., 2011).
- pore-scale reactive transport models (Huber and Shafei, submitted).
- multiphysics (Parmigiani et al., 2008).
- noble gas diffusion for themochronology (Huber et al., GCA, 2011).
- multiphase reactive flows in porous media (Parmigiani et al., JFM, 2011).
- multicomponent coupled diffusion problems (Huber et al., JCP, 2010).

We are proposing a class for graduate student on lattice Boltzmann methods for geosciences (EAS 8013).

]]>Our group studies how pore-scale processes influence porous media flows at much greater scales (e.g. continuum or field scale). We use a combination of numerical calculations and lab experiments to study

- self-organization of multiphase flows in porous media during the injection of non-wetting fluids.
- multiphase transport at sharp transition in porosity/permeability.
- reconstructing porosity-permeability of anisotropic porous media.
- evolution of a porous medium and porosity-permeability correlations during melting/dissolution or precipitation.
- reduction of effective permeability with frequency during transient applied stress in the pore-fluid.
- reactive transport models at the pore-scale, the effect of physical (grain) and chemical (distribution of reactive surfaces) heterogeneities on reactive flows.
- the effect of the driving force for the flow (buoyancy versus pressure) on dispersion and solute transport.

These conceptual problems are motivated by questions associated with CO2 sequestration, the exsolution and transport of volatiles in magmatic environment, bio-geochemical cycles in porous media, groundwater remediation and geothermal flows.

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