Box model simulation results and plotting script for study on HDN effect in fuel cell propelled aircraft plumes

This repository contains the LCM box model simulation results and the plotting script to reproduce the figures of the manuscript'Hillenbrand, Unterstrasser: A new ice crystal formation pathway in contrails generated by fuel cell propelled aircraft' Please follow the steps to reproduce the figures: Download and unzip the archive file. Navigate to the destination folder and install the virtual environment(e.g., in a Miniforge prompt) using:conda env create --file environment.yml Activate the virtual environment with: conda activate HDN_manuscript Reproduce the figures by running the Jupyter Notebook 'HDN_paper_plots.ipynb'.Activate the previously created python kernel 'HDN_manuscript'. The figures are saved in the (created) subdirectory './plots'. The directory './data' contains the simulation results produced with the LCM box model, and the input data for the simulations.Each subdirectory contains the data of a single simulation, split into thermodynamic and microphysical results.Meta data files contain the information to interpret the results. ./data/dilution_data:Contains the input data for the box model simulations. dil_fludiles.dat: Dilution data reproduced from turbo jet data. dil_nephele.dat: Dilution data measured behind a Fuel Cell emulator, described in https://doi.org/10.5194/egusphere-2026-2887 dil_cfd.dat: Dilution data created from CFD simulation of exhaust behind Fuel Cell propelled aircraft. ./data/validate_HDN_MN:Contains the simulation results for the validation of HDN implementation using the Mystery nozzle benchmark case from DOI: 10.1177/0957650918758779. T388: Initial temperature T=388 K T388_sigma095: Initial temperature T=388 K, using surface tension \sigma = 0.95*\sigma_{ref} T388_sigma105: Initial temperature T=388 K, using surface tension \sigma = 1.05*\sigma_{ref} T417*: same as above with initial temperature T=417 K ./data/HDN_convergence:dt<delta_t>_ntime<n_fine>_<>:Simulations using the time step delta_t for the diffusion process in the LCM box model.This timestep is refined <n_fine> times, when HDN becomes important.Possible <suffixes>: 'ref': Reference simulation 'delta10': Use relative heat emission factor \delta=0.1, rest as in 'ref' simulation 'eta=50': Use overall propulsion efficiency of \eta=0.5, rest as in 'ref' simulation 'dilneph': Use the dilution data from 'dil_nephele.dat', rest as in 'ref' simulation 'dil_nep_diffnuc': Use the dilution data from 'dil_nephele.dat' andchange order of microphysical processes, such that diffusion is solved before nucleation in each time step, rest as in 'ref' simulation ./data/paramStudy:Simulations to evaluate the effect of HDN in various scenarios, see Table 4 in manuscript. Tamb<T_amb>_gamma<gamma>: Prescribe ambient temperature T_amb and the relative water vapor emission factor \gamma.Within each of these folder the following simulations are present: 'reference': Simulation using reference values given in Table 4 'aero10': Use aerosol number concentration of 10 cm^-3 'dilneph': Use dilution from 'dil_nephele.dat' 'eta50': Use overall propulsion efficiency of \eta=0.5 The folders with T_amb = 218 K additionally contain: 'aero1000': Use aerosol number concentration of 1000 cm^-3 'delta10': Use relative heat emission factor \delta=0.1 'delta30': Use relative heat emission factor \delta=0.3 'dilflud': Use dilution from 'dil_fludiles.dat' 'dilinit50': Use an initial air-to-fuel ratio of 50 'dilinit200': Use an initial air-to-fuel ratio of 200 'kantro': Use the correction of HDN rate by Kantrowitz 'sigma095': Use surface tension \sigma = 0.95*\sigma_{ref} 'sigma105': Use surface tension \sigma = 1.05*\sigma_{ref}