FLINT — Fortran Library for INtegrated Thermochemistry

FLINT is a lightweight, modular Fortran library for thermochemistry in reactive flow simulations.

It provides a clean interface to thermodynamic, transport, and chemical source term models, designed to integrate seamlessly into CFD solvers while keeping thermochemistry decoupled from CFD complexity.

Small but powerful — like the stone it’s named after — FLINT provides the spark for complex thermochemical simulations.

Why FLINT?

• Decoupled thermochemistry
  Develop and test chemical models independently of CFD solvers.

• Modular & extensible
  Plug in different chemistry, transport, or equilibrium models with minimal coupling.

• Optional Cantera backend
  Access advanced kinetic models and validation when needed.

• Production-ready
  Ships with a library of verified chemical mechanisms.

• Developer-friendly
  Automated YAML-to-Fortran (YTF) code generation for mechanisms and models.

Capabilities

• Ideal-gas thermodynamics
• Real-fluid thermodynamics (pressure–enthalpy tables)
• Transport properties (viscosity, thermal conductivity, diffusion)
• Finite-rate chemical kinetics
• Equilibrium chemistry
• 0D reactors and source-term evaluation

A Taste of FLINT

Thermochemistry setup in FLINT is explicit, modular, and solver-agnostic

program taste_of_flint
  use FLINT_Load_ThermoTransport
  use FLINT_Load_Chemistry
  implicit none

  integer :: err

  ! Load ideal-gas thermodynamics
  err = read_idealgas_thermo(folder='WD/INPUT')
  if (err /= 0) stop "Error loading thermodynamics"

  ! Load chemical mechanism
  err = read_chemistry(folder='WD/INPUT')
  if (err /= 0) stop "Error loading chemistry"

end program taste_of_flint

Quick Start

git clone https://github.com/MarcoGrossi92/FLINT.git
cd FLINT
./install.sh build --compiler=gnu

Cantera support is optional and disabled by default. If enabled, it is strongly recommended to install Cantera externally first.

Requirements

• Fortran compiler (GNU or Intel)
• CMake ≥ 3.23
• Python ≥ 3.8 (optional, for utilities)
• C compiler (for SUNDIALS support)

Optional:

• Cantera ≥ 2.5

Documentation

📘 Full documentation, theory, and examples: https://marcogrossi92.github.io/FLINT/

See the docs for:

• Installation details
• API reference
• Examples and test cases
• YAML-to-Fortran workflow

License

GNU General Public License v3.0 See LICENSE.

Acknowledgments

FLINT incorporates concepts and algorithms from:

• NASA CEA — Chemical Equilibrium with Applications https://github.com/nasa/cea