The Documentation of the RAPID Simulation Code

RAPID (Representative Approach for Particle-Integrated Disks) is a high-performance 1D numerical framework designed to simulate the co-evolution of gas and dust in protoplanetary disks using a hybrid Euler-Lagrange approach.

The code specifically targets the formation of pressure traps at dead zone edges, enabling the investigation of dust accumulation and planetesimal formation nurseries with high computational efficiency.

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Contents

• The Documentation of the RAPID Simulation Code
• Introduction
• Getting started
  • 1. Get the source code from GitHub
  • 2. Install the rapidsim Python package
• Understanding YAML configuration files
• Expected output
  • HDF5 snapshot structure

The RAPID model

• Physical Background
  • Hybrid Euler-Lagrangian Approach
  • Gas Dynamics
  • Dust Dynamics and Growth
  • Photoevaporation
• Numerical Implementation
  • Spatial Discretization and Grid Geometry
  • Gas–Particle Coupling and Temporal Integration
  • Time Integration and Stability Criteria
  • Mapping Discrete Dust Particles to a Radial Surface Density Field
  • Field-Dependent Boundary Condition Approach

RAPID Notebooks

• RAPID Notebooks
  • Equidistant grid convergence test
  • Logarithmic grid convergence test
  • Mass conservation test
  • Owen and Picogna flux tests comparison
  • Viscous ring spreading test

User Guide

• API Reference
  • Configuration Module
  • Initialize Disk
  • Disk Physics Module
  • Boundary Conditions Module
  • Simulation Core Module
  • Utils Module

Indices and tables

• Index

• Module Index

• Search Page

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How to Cite

If you use the RAPID code for your research, publications, or presentations, we kindly ask you to cite the following papers to support the development of this project.

Primary Reference for the Code

The main reference describing the RAPID model, the trajectory-based Lagrangian approach, and its implementation is:

• Tarczay-Nehéz, D. (2026): Trajectory-based dust evolution in disks: first results from the RAPID simulation code, Celestial Mechanics and Dynamical Astronomy, 138(1), 6. https://doi.org/10.1007/s10569-026-10278-2

Physical Foundation and Dead Zone Model

For the physical background regarding the dead zone edges, viscosity transitions, and the vortex-vortex interaction models implemented in RAPID, please cite:

• Regály, Zs., Juhász, A., & Nehéz, D. (2017): Interpreting Brightness Asymmetries in Transition Disks: Vortex at Dead Zone or Planet-carved Gap Edges?, The Astrophysical Journal, 851(2), 89. https://doi.org/10.3847/1538-4357/aa9a3f

BibTeX

For your convenience, you can use the following BibTeX entries:

@article{TarczayNehez2026,
    author = {Tarczay-Neh{\'e}z, D{\'o}ra},
    title = {Trajectory-based dust evolution in disks: first results from the RAPID simulation code},
    journal = {Celestial Mechanics and Dynamical Astronomy},
    year = {2026},
    volume = {138},
    doi = {10.1007/s10569-026-10278-2}
}

@article{Regaly2017,
    author = {{Reg{\'a}ly}, Zs. and {Juh{\'a}sz}, A. and {Neh{\'e}z}, D.},
    title = "{Interpreting Brightness Asymmetries in Transition Disks: Vortex at Dead Zone or Planet-carved Gap Edges?}",
    journal = {The Astrophysical Journal},
    year = 2017,
    volume = {851},
    doi = {10.3847/1538-4357/aa9a3f}
}