Simulation data related to compute project NHRZIB - Volume-averaged modeling and simulation of structured catalysts: assumptions on the effective diffusivity in steam-methane reforming

# README: Volume-averaged modeling and simulation of structured catalysts: assumptions on the effective diffusivity in steam-methane reforming The files listed here correspond to summarized 3-D and 1-D numerical simulation data for a catalytic steam-reforming reactor. In the following, the folder structure of the repository is explained. Later, the usage case of the here contained Python scripts is also detailed. All of the data was generated in the framework of the NHR@ZIB compute project bbi00024, titled "Volume-averaged modeling and simulation of structured catalysts: assumptions on the effective diffusivity in steam-methane reforming". An abstract of the project can be found in [Zenodo](https://doi.org/10.5281/zenodo.17846984). ## 1. Folder: 3DSolverSROpenFOAM This folder contains summarized OpenFOAM 3-D data for a catalytic steam-reforming reactor. There are 4 main cases evaluated. So-called "Sim1" and "Sim2" cases correspond, respectively, to assumed Unity Lewis and Fickian-based diffusive transport models. Also "impermeable" or "porous" data corresponds to catalyst reactors assumed either as impermeable (porosity zero) or porous (nonzero porosity) materials. Therefore, *impermeable_Sim_1.csv* is a CSV datafile containing different streamwise-dependent volume-averaged flow properties of an impermeable reactor simulated with a Unity Lewis diffusive transport assumption. The files with added prefix *with_rr* refer exclusively to streamwise-dependent volume-averaged reaction-rates. ## 2. Folder: Homogeneous_SR_Reactor This folder contains information on so-called homogeneous, pseudo 1-D simulations (plug-flow reactor models). Different data is available for pseudo 1-D reactors assumed either homogeneous in space (time-dependent reactors), or steady flow reactors. The files with prefix *HomogeneousReactorData* simply list reactor outlet flow properties (and chemical equilibrium properties). The files with prefix *History* report streamwise-dependent mass-fractions in the reactor. ## 3. Folder: IterativeEquivDiff1D This folder contains summarized 1-D simulation data. In the folders with prefix *EquivD*, we have stored 1-D simulation data using streamwise-dependent effective mass-diffusivity coefficients. The form of said diffusivity coefficients follows from 3-D data (Folder *3DSolverSROpenFOAM*), and is available on the corresponding *txt* files which have the same name prefix as the corresponding *EquivD* folder. In the folders named *ImpermeableUL_1DVel* and *ImpermeableUL_3DVel*, it is possible to find results of a parametric evaluation of the outlet flow of the 1-D reactor as a result of a systematic change in (uniform) effective mass-diffusivities. The parametric table is found within the folder, named *TableDY_ImpUL.txt*. The results of 1-D simulations run with the mass diffusivities yielding the minimum error in the corresponding file *TableDY_ImpUL.txt* are found in the folders with prefix *Optimum*. ## 4. Folder: Unsteady1DSolverSR This folders contains 1-D simulation data for the aforementioned 4 cases of study (Impermeable, Porous, Unity Lewis, and Fickian-based transport). Both property tables and flow snapshots are stored within the folder. ## 5. Folder: ReferenceData This folders contains both experimental and numerical simulation reference data for a similar steam-methane reforming reactor analyzed by [Palma et al. (2014)](https://doi.org/10.1016/j.fuel.2014.06.043) and [Palma et al. (2016)](https://doi.org/10.1016/j.jclepro.2015.09.004). Each text file is a table with extracted values of the relevant plots presented in the aforementioned references (streamwise-dependent concentration profiles, and temperature-dependent outlet flow). ## 6. Folder: methaneSteamReformingAndWGS_NiCat_HabermanYoung This folders contains a steam-methane reforming chemical reaction mechanism. The reaction mechanism is available on cti, dat and yaml formats. The reactions and rate constants correspond to those published by [Haberman and Young (2004)](https://doi.org/10.1016/j.ijheatmasstransfer.2004.04.010). The temperature-dependent thermodynamic properties and transport properties correspond to those used in the [GRI-Mech 3.0](http://www.me.berkeley.edu/gri_mech/) hydrocarbon combustion mechanism. The chemical reaction mechanism is intended to be read with [Cantera](https://cantera.org/). ## 7. Folder: Paper_plots This folder contains relevant visualizations generated with the Python scripts to be described next. ## 8. Python Scripts Most of the python scripts listed here are supported with the modules *inputs_catalyst.py* and *datafiles_catalyst.py* which contain information about the input parameters to the simulations, as well as references to the relevant datafiles for each type of simulation contained in the aforementioned folders. ### Plot-SR-Palma.py This script generates a plot of temperature-dependent outlet-flow concentration. The only relevant input parameters to the script are the following flags. The flag *time_space* specifies whether the plot will load data from homogeneous or steady-flow reactors (see description of folder *Homogeneous_SR_Reactor*). The flag *porous_reactor* specifies whether the plot corresponds to a porous or impermeable reactor. The combination of the previous 2 flags requires the specification of the input directory *Homogeneous_SR_Reactor* and of an output directory to store the generated plots. ### Sim_Results_X_z.py This script generates streamwise-dependent concentration plots summarizing the information from the 3-D and 1-D reactor simulations. The necessary input is simply the specification of the flags *unityLewis* and *porous* to specify which of the 4 cases must be loaded. The data itself is loaded with the help of the module *datafiles_catalyst.py* and *inputs_catalyst.py*. Besides that, the script requires the specification of the chemical mechanism file (can also be retrieved with the data member *datafiles_catalyst.chem_mech_gas*), and of an output directory to store the generated plots. ### Sim_Results_RR_z_Repo.py This script generates streamwise-dependent normalied reaction-rate plots summarizing the information from the 3-D and 1-D reactor simulations. The required inputs are the same as those for the script *Sim_Results_X_z.py* ### Sim_Results_H2_Bal_z_Repo.py This script generates streamwise-dependent transport term plots summarizing the information from the 3-D and 1-D reactor simulations. The required inputs are the same as those for the script *Sim_Results_X_z.py*. Additionally, it is necessary to specify an output directory to store the obtained equivalent 1-D streamwise-dependent effective diffusivity obtained from 3-D data, this is the string specified by *output_dir_Dequiv*. The other string *output_dir* simply refers to the directory to store the generated plots. ### OptimumDequivFromTables_Repo.py This script generates plots regarding the parametric evaluation of the change of effective diffusivities on the results of 1-D simulations. The required inputs are again the flags *sw_porous* and *unityLewis* specifying the simulation case, as well as the directories containing the equivalent effective diffusivities from 3-D data (folder *IterativeEquivDiff1D*) and the tabulated diffusivity-dependent outlet-flow estimation error (also in the folder *IterativeEquivDiff1D*). Additionally, the user should specify the name of a so-called inert species in the reaction mechanism. This corresponds to the chemical species which observes a value not determined by a transport equation, but rather, by the residual required to satisfy continuity from the summation of all other chemical species (sum of all Ys = 1). For the used reaction mechanism by [Haberman and Young (2004)](https://doi.org/10.1016/j.ijheatmasstransfer.2004.04.010), the inert species to select should be water ('H2O'). ### Plot_EffectiveDiff_Repo.py This script generates a plot with the determined equivalent 3-D effective diffusivities, as well as a plot with the 1-D simulation results observing the use of said equivalent 3-D effective diffusivities. The required inputs are the flags *sw_porous* and *unityLewis*, as well as a flag *sw_3DVel* which specifies whether the 1-D simulation using a 3-D streamwise velocity field, or the inherent 1-D velocity field is plot. Depending on the choice of flags, the directory containing the corresponding 1-D simulation (and the last snapshot *txt* file) must be specified with the string *SimDequiv_datafile*. The directory containing the equivalent effective diffusivities from 3-D data (folder *IterativeEquivDiff1D*) must be specified as well. The plots will be stored in the folder *IterativeEquivDiff1D*. Acknowledgements The author gratefully acknowledges the computing time made available to them on the high-performance computer "Lise" at the NHR Center NHR@ZIB. This center is jointly supported by the Federal Ministry of Research, Technology and Space and the state governments participating in the NHR ( www.nhr-verein.de/unsere-partner )