Two-Fluid Plasma Model Simulation

This code was completely written by Claude in Windsurf with user prompting.

This repository contains a PyTorch implementation of a two-fluid plasma model based on "Approximate Riemann solver for the two-fluid plasma model".

Features

• Separate conservation equations for electron and ion fluids
• Full Maxwell's equations
• GPU-accelerated using PyTorch
• Second-order spatial reconstruction with minmod limiter
• TVD Runge-Kutta time integration
• Configurable charge parameters
• Shock-capturing capability

Installation

This project uses Poetry for dependency management. To install:

poetry install --no-root

Usage

Run the shock simulation with default parameters:

poetry run python shock_simulation.py

Configure simulation parameters:

poetry run python shock_simulation.py --resolution 500 --final-time 0.2 --plot-interval 0.01 --charge 10.0

Options:

• --resolution, -r: Number of spatial grid points (default: 500)
• --final-time, -t: Final simulation time (default: 0.2)
• --plot-interval, -p: Time between plots (default: 0.01)
• --charge, -c: Magnitude of species charge (ion: +charge, electron: -charge) (default: 10.0)

Development History

The complete development conversation between the human developer and Claude 3.5 Sonnet is available in TRANSCRIPT.md. This transcript shows the iterative process of implementing the model, debugging issues, and making improvements.

A YouTube video of an attempt to develop this code with AI

Latest Simulation Results

The image shows the final state of the simulation with:

• Density profiles for electrons and ions
• Velocity components
• Electric and magnetic field components
• Temperature evolution

Implementation Details

The simulation uses normalized units where:

• Ion mass = 1.0
• Speed of light = 1.0
• μ₀ = 1.0, ε₀ = 1.0
• Configurable charge parameter (default: qi = +10, qe = -10)

Initial conditions are based on a modified Brio-Wu shock setup with:

• Density discontinuity (1.0 vs 0.125)
• Pressure discontinuity (0.5 vs 0.05)
• Magnetic field discontinuity
• Zero initial velocities