Pore scale numerical simulation of flow and heat transfer non-equilibrium in randomly packed bed

The complex pore structure of porous media in packed beds leads to randomness and non-uniformity of flow and heat transfer. In this paper, the pore-scale method is used to numerically study the flow and heat transfer in 3D randomly packed bed. The average value and root-mean-square (RMS) of variables are used to evaluate the non-equilibrium characteristics of temperature and velocity. The results demonstrate that the packed bed consistently exhibits non-equilibrium phenomena due to the influence of porous media structure. The peak of thermal non-equilibrium occurs at the location with the largest temperature difference between gas and solid phases, while the peak of flow non-equilibrium occurs after reaching maximum temperature. With increasing inlet velocity, there is an expansion in both local velocity and temperature disturbance range, leading to a wider non-equilibrium region. However, the trend of non-equilibrium between flow and heat transfer is different.