Diffusion-compaction_coupling_Data_and_postprocessing_codes

This repository contains the data, simulation outputs, and analysis code accompanying a paper on pore pressure feedback in granular beds — specifically fluidized/aerated particle beds relevant to geophysical and industrial flows. The work models 1D porous media flow with compaction, excess pore pressure diffusion, and dynamic permeability. The repository is organized by figure, with each folder containing raw simulation data (CSV outputs from MFiX), a Jupyter notebook to reproduce the plot, and the resulting PDF figure: Figure 1 — Permeability analysis at minimum fluidization velocity (Umf), comparing simulations to theory. Figure 2 — Validation of a custom 1D excess pressure solver (with/without compaction source term) against MFiX numerical simulations. Figure 3 — Four-panel decomposition of pressure contributions across varying bed heights. Figure 4 — Fourier mode convergence study for the analytical/semi-analytical solution. Figure 5 — How initial and final packing fractions (ε) vary with bed height H. Figure 6 — Comparison of an algebraic model for the fluidization parameter ψ against full simulations. Figures 7–11 — IMEX (implicit-explicit) solver results, including dam-break implementations inspired by Aravena (2021) and grid-search parameter studies with dynamic permeability. Figure 12 — Maps of fitted diffusivity (D_fit), predicted diffusivity (D_pred), and ψ₀ for air, exploring parameter space. The codebase uses Python (NumPy, Numba) for solvers and Jupyter notebooks for visualization, with MFiX providing reference Two-Fluid Method (TFM) simulation data.