Multi-region coupling computational fluid dynamics simulation of the underground compressed air energy storage process.

This article focuses on the development and validation of a multi-region coupled numerical simulation solver for underground Compressed Air Energy Storage (CAES) systems, addressing both compressible air flow within storage caverns and porous air flow in surrounding rock. Using the open-source software OpenFOAM, the solver integrates transient compressible flow and porous flow equations with coupled boundary conditions, enabling more accurate simulation of pressure, temperature, leakage rates, and flow fields compared to previous methods. Validation against experimental data from the Kamioka CAES field test demonstrates the solver’s reliability, while multi-condition simulations reveal how variations in rock permeability, porosity, and air injection rates affect system performance and flow dynamics. The study provides technical insights and an open-source tool to support site selection, construction, and operational strategies for underground CAES facilities.