Speaker
Description
Conventional pore-scale approaches face a trade-off between accuracy and computational efficiency. While direct numerical simulation (DNS) explicitly resolves fluid-solid interfaces, it typically requires boundary-conforming meshes, limiting its applicability to complex geometries and large image-based rock samples. Single-domain micro-continuum models based on the Darcy-Brinkman-Stokes (DBS) formulation provide an alternative by enabling simple meshes and governing equations defined over the entire computational domain using a local porosity field, allowing the simulation of billions of voxels with relative ease. The Brinkman equation is used to penalise the solid phase by introducing an infinitesimally small permeability, and can also be used to integrate unresolved porosity within a multiscale framework. However, the Brinkman penalisation does not recover the correct boundary conditions at fluid–solid interfaces, leading to non-negligible errors in flow predictions and permeability estimates, as well as non-physical behaviour in multiphase flow and reactive transport.
In this study, we introduce a Volume of Solid (VoS) approach for pore-scale modelling in porous media. The VoS formulation derives a unified governing equation through volume averaging, consistently embedding fluid and solid physics within a single framework. Unlike classical DBS methods, VoS avoids empirical permeability assignments in the solid phase and recovers the correct limiting behaviour at fluid-solid interfaces under grid refinement, while matching DNS accuracy for interfacial fluxes and retaining simple voxel-based meshing.
The method is implemented in GeoChemFoam and validated against analytical solutions and benchmark pore-scale flow problems, demonstrating improved agreement with DNS compared to conventional DBS formulations. The VoS framework is extended to reactive transport, multiphase flow, and elastic stress computation, and its performance is assessed by comparing it with DNS in cases where standard penalisation methods exhibit significant limitations. This framework provides a solid basis for large-scale porous media simulations that, in future work, can be coupled with Darcy–Brinkman–Stokes models for multiscale modelling.
| Country | United Kingdom |
|---|---|
| Acceptance of the Terms & Conditions | Click here to agree |
