vle-thermo 0.3.1

Vapor-liquid equilibrium thermodynamic calculator: 22+ cubic EOS, activity models, mixing rules, flash algorithms
Documentation

vle-thermo

Vapor-liquid equilibrium (VLE) thermodynamic calculator in Rust.

Crates.io Docs.rs License: MIT

A modern Rust port of two legacy thermodynamic codebases (VB6 ~15,000 lines + Pascal ~2,500 lines) supporting:

  • 22+ cubic equations of state — Peng-Robinson, RKS, van der Waals, Schmidt-Wenzel, Patel-Teja, and more
  • 5 activity coefficient models — Wilson, van Laar, Margules, Scatchard-Hildebrand, Ideal
  • 11 mixing rules — Classical (IVDW, IIVDW), Wong-Sandler, Huron-Vidal, MHV1/MHV2
  • 6 saturation pressure correlations — Antoine, Riedel, Müller, RPM, polynomial, Maxwell
  • 6 flash calculation types — bubble/dew point (T/P), isothermal, adiabatic (WIP)
  • Parameter regression — kij (binary interaction) and Aij (activity model) (WIP)

Status

0.1.x — types, enums, and data structures are stable. Numerical kernels (Cardano solver, Newton-Raphson, Broyden, Rachford-Rice, flash algorithms) are under active development across Milestones 5–7 of the modernization plan. Semver promises do not apply until 1.0; treat 0.1.x as a pre-release.

See the roadmap for what's shipped vs. planned, and the modernization plan for the phase-by-phase technical detail.

Install

[dependencies]
vle-thermo = "0.1"

Or with cargo add:

cargo add vle-thermo

The crate is no-pyo3 by default — PyO3 bindings are gated behind the optional python feature and are only needed when maturin builds the Python wheel.

Quick look

use vle_thermo::{CubicEos, ActivityModel, MixingRule, SatPressureModel};

let eos = CubicEos::PengRobinson;
let activity = ActivityModel::Wilson;
let mixing = MixingRule::WongSandler;
let psat = SatPressureModel::Antoine;

println!("using {eos:?} + {activity:?} + {mixing:?} + {psat:?}");

Full API docs: https://docs.rs/vle-thermo.

Units

Numerical kernels use the thesis's canonical internal units:

Quantity Unit
Temperature K (absolute)
Pressure kPa (absolute)
Molar energy kJ/kmol
Molar entropy kJ/(kmol·K)
Molar volume cm³/mol
Amount kmol

For user-facing input/output in arbitrary units (including gauge pressure, °C, °F, psi, barg, mmHg, etc.) see the companion crate vle-units.

Origin

Based on the thesis "Desarrollo de un Programa Computacional para el Cálculo del Equilibrio Líquido Vapor de Mezclas Multicomponentes bajo el Ambiente Windows" (Jackson & Mendible, Universidad Simón Bolívar, 1999), with additional models from Da Silva & Báez (1989). See the research paper (English translation) for the algorithms and their academic references.

License

MIT. See LICENSE.