Data and code for: Transverse structural reorganization drives non-monotonic concentration variance in porous media

This archive contains simulation data, post-processing scripts, derived analysis files, and visualization videos for studying non-monotonic concentration variance during solute transport in idealized multi-channel systems and porous-media domains. The `Mutichannel_model` folder contains MATLAB scripts for the idealized multi-channel model. These scripts compute concentration variance at the 0.5 mean-concentration location, evaluate modal contributions, and compare the time evolution of mixing-related quantities for different channel numbers. The `channels_analysis_openfoam` folder contains MATLAB post-processing scripts and derived OpenFOAM channel-simulation results for `Pe = 100`. It includes concentration variance data at the `Cbar = 0.5` front, variance-budget CSV files for different channel counts, and cached MATLAB files used for plotting selected budget terms. The `PorousMediaSimulation` folder contains OpenFOAM porous-media simulation outputs and MATLAB post-processing scripts. The included scripts extract concentration variance, calculate modal energy of concentration fluctuations, count main-interface intersections, and compare porous-media results with the idealized channel model. The `Videos` folder contains visualization movies of concentration transport and variance evolution for both the multi-channel model and porous-media simulations. Overall, the archive provides the data and scripts needed to reproduce the main post-processing analyses of concentration variance, variance-budget behavior, modal-energy evolution, and interface structure in the studied transport systems.