jf1uids 0.1.1

conservative, differentiable, radial 1d fluid solver with astrophysical modules

jf1uids - Differentiable Conservative Radially Symmetric Fluid Simulations and Stellar Winds

Welcome to the repository of jf1uids, a 1d radial fluid solver written in JAX.

jf1uid is written in a way such that mass and energy are conserved based on the approach of Crittenden and Balachandar (2018) with a MUSCL-Hancock fluid solver. Note that for any general pupose (non-radial) problem consider using JAX-Fluids.

The solver's code can be found in the jf1uis folder. You can find a simple example for getting started under simple_example.ipynb.

Installation

For now, during the double-blind review phase, we recommend downloading the repository on https://anonymous.4open.science/r/jf1uids/. You can then test the code by running and adapting the example notebooks.

You will need to have

• jax
• optax
• matplotlib
• astropy (for unit-handling for the stellar wind)
• scipy (for the Weaver (1977) solution)
• numpy

installed.

Reproducing the results from the paper

All the results from the paper can easily be reproduced via the notebooks provided

• figure 1 → conservational_properties.ipynb: For a radial shock problem, conservation of mass and energy in jf1uids are showcased.
• figure 2 → gradiends_through_stellar_wind.ipynb: The gradients of the final fluid state with respect to the wind's velocity are analyzed.
• figure 3 → wind_parameter_optimization.ipynb: Finding wind parameters from the final fluid state via gradient-descent is shown.

Roadmap

• Implement a conservative 1d radial fluid solver with simple to implement yet powerful numerical schemes.
• Implement a simple stellar wind model, first analyses on the gradients of the final fluid state with respect to the wind parameters.
• Implementation of higher-order reconstruction methods like WENO-Z+, etc.
• Implementation of different Riemann solvers
• Implementation of a shock finder
• Implementation of a simple cosmic ray model based on the energy dissipation in shocks
• Two-fluid cosmic-ray model
• Full-spectrum cosmic ray modeling