Treffer: A compressible pore-scale numerical simulation of hydrogen flow into brine: Application to underground hydrogen storage

This study investigates the dynamics of hydrogen-brine flow in idealized pore geometries, with the aim of improving underground hydrogen storage in saline aquifers. Direct numerical simulations (DNS) using Open-FOAM are carried out to assess the influence of key parameters including injection flow rate, pore geometry, dynamic contact angle, and fluid compressibility on immiscible displacement at the pore scale. Results demonstrate marked differences between compressible and incompressible models in terms of brine sweep efficiency, interface displacement patterns, and pressure drop for a given flow rate. Incompressible simulations fail to capture critical phenomena such as hydrogen bubble formation and associated pressure fluctuations. Variations in flow rate and geometric constriction significantly impact residual brine saturation and inlet pressure dynamics; lower rates reduce pressure buildup and leakage risk while increasing storage efficiency. Incorporating a dynamic contact angle reduces the capillary resistance, accelerates the flow, and mitigates pressure peaks compared to static angle models. Overall, this work demonstrates the applicability of OpenFOAM to multiphase compressible hydrogen-brine flows at the pore scale, providing application-specific validation and novel insights to guide the design and optimization of underground hydrogen storage systems.