MagmaFOAM-1.0: a modular framework for the simulation of magmatic systems

Abstract

Abstract. Numerical simulations of volcanic processes play a fundamental role in understanding the dynamics of magma storage, ascent, and eruption. The recent extraordinary progress in computer performance and improvements in numerical modeling techniques allow simulating multiphase systems in mechanical and thermodynamical disequilibrium. Nonetheless, the growing complexity of these simulations requires the development of flexible computational tools that can easily switch between sub-models and solution techniques. In this work we present MagmaFOAM, a library based on the open-source computational fluid dynamics software OpenFOAM that incorporates models for solving the dynamics of multiphase, multicomponent magmatic systems. Retaining the modular structure of OpenFOAM, MagmaFOAM allows runtime selection of the solution technique depending on the physics of the specific process and sets a solid framework for in-house and community model development, testing, and comparison. MagmaFOAM models thermomechanical nonequilibrium phase coupling and phase change, and it implements state-of-the-art multiple volatile saturation models and constitutive equations with composition-dependent and space–time local computation of thermodynamic and transport properties. Code testing is performed using different multiphase modeling approaches for processes relevant to magmatic systems: Rayleigh–Taylor instability for buoyancy-driven magmatic processes, multiphase shock tube simulations propaedeutical to conduit dynamics studies, and bubble growth and breakage in basaltic melts. Benchmark simulations illustrate the capabilities and potential of MagmaFOAM to account for the variety of nonlinear physical and thermodynamical processes characterizing the dynamics of volcanic systems.

Short-term magma-carbonate interaction: A modelling perspective

“…The volume of fluid method is adopted in OpenFOAM to resolve the position and shape of the interface separating two fluids or phases (e.g., liquid-gas). As already shown by Brogi et al (2022), we remark that the details of the numerical solver and its parameters may affect the details of the interface geometry between the contaminated and uncontaminated melts. However, convergence tests and comparison with experimental observations (Appendix C.1) have demonstrated that the fluid solver reproduces well the overall dynamics of the mingling of two liquids enhanced by a rising bubble.…”

“…The mingling dynamics between a contaminated, low-viscosity, gas-rich magma pocket and the uncontaminated melt are simulated using the opensource computational fluid dynamics software OpenFOAM, which has been already tested and benchmarked on volcanological problems (Brogi et al, 2022). The numerical simulations are performed with the multiphase solver icoReactingMultiphaseInterFoam which can deal with multiple incompressible non-isothermal phases and phase change.…”