Combustion Toolbox v1.2.0 Released

Combustion Toolbox v1.2.0 is now available! This release introduces a new turbulence module, a refactored equation-of-state system, significant performance improvements, and multiple usability enhancements across the entire ecosystem.

New Features and Enhancements

1. New +turbulence subpackage

A dedicated module for turbulence analysis.

• HelmholtzSolver class:

  • Implements Helmholtz decomposition to separate 3D velocity fields into:
    • Solenoidal Component (divergence-free)
    • Dilatational Component (curl-free)
  • Includes validation methods to ensure decomposition accuracy.

• TurbulenceSpectra class:

  • Computes turbulence energy spectra using:
    • Spherical Averaging
    • Cross-Plane Averaging (configurable for x, y, or z axes)
  • Provides functions to validate energy cascade properties and visualize spectra.
  • Functions to compute probability density functions (PDFs) and integral length scales.
  • New routines for computing and plotting joint-PDFs with advanced visualization features.

• VelocityField class:

  • Encapsulates 3D velocity field data (u, v, w) and offers:
    • Methods for computing magnitudes.
    • Utilities for normalizing and scaling velocity fields.

2. New HTR Data Utility classes

A dedicated HTR data handling module has been introduced to facilitate postprocessing and data analysis from HTR solver simulations.

• HTR Data Handling:
  • HTRDataReader class: Reads simulation data from the HTR solver, extracting velocity, temperature, pressure, and species concentration fields.
  • HTRDataAverage class: Provides postprocessing utilities for averaging HTR simulation results, computing spatial and temporal averages of key flow properties.

3. Refactored EquationState class

Significant refactoring has been performed in the Mixture class to improve flexibility, maintainability, and computational efficiency.

• Introduced EquationState as an abstract base class for different equations of state.
• New EquationStateIdealGas class implements the ideal gas law:
  • getPressure(T, V): Computes pressure using $P=\frac{RT}{V}$.
  • getVolume(T, P): Computes molar volume using $V=\frac{RT}{P}$.
• This structure prepares the framework for future real gas models (e.g., Peng-Robinson, BKW, Heuzé EOS).

4. Improved Mixture class Computation

• Refactored Methods:

  • updateComposition() to handle composition changes independently.
  • updateThermodynamics() to compute thermodynamic properties without redundant recalculations.

• Optimized State-Setting:

  • setTemperature(), setPressure(), and setVolume() now trigger only necessary updates, avoiding redundant logic.

• Performance Improvements:

  • Removed unnecessary unit conversions in shock and detonation solvers.
  • Optimized the ChemicalSystem class by avoiding get methods for indexElements and indexSpecies, reducing overhead.
  • Improved Units class performance by replacing handle functions with direct conversion factors.

• New MixtureConfig class:

  • Introduced to handle configuration settings for Mixture objects.
  • Supports mol, molar fraction, or mass fraction composition units.
  • Allows for compact composition output using the FLAG_COMPACT option.

• Include setTemperatureSpecies method to define initial temperatures for each species in a mixture.

  • Key Features:

    • Custom initialization of temperatures for individual species.
    • Automatic computation of equilibrium temperature.
    • Thermodynamic recalculations after changes in composition.

  • Example Usage:

    set(mix, {'CH4'}, 'fuel', 1);
    set(mix, {'O2'}, 'oxidizer', 1);
    setTemperatureSpecies(mix, [300, 350]);
    

5. New Standalone Installer (INSTALL_STANDALONE.sh)

A cross-platform Bash script to automate installation of the standalone version.

• Key Features:

  • Detects the operating system (Windows, macOS, or Linux).
  • Fetches the latest release assets from GitHub.
  • Extracts and executes the appropriate installer.

• Usage Instructions:

  sh INSTALL_STANDALONE.sh
  

• Repository Optimization:

  • Standalone installers are no longer stored in the repository.
  • They are now included as release assets to reduce repository size and improve maintainability.

Bug Fixes and Refinements

• Fixed errors in thermochemical property calculations using the frozen approximation.
• Resolved issues with internal energy and enthalpy calculations in the Species object.
• Fixed molesGuess bug in Mixture, ensuring proper behavior when indexProducts differs from indexSpecies.
• Corrected errors in rocketFAC method for subsonic regions.
• Fixed setListSpecies method when complete combustion is selected.
• Extended equivalence ratio range in EXAMPLE_HP_COMPLETE_INCOMPLETE to observe soot formation.
• Updated comments and documentation for clarity and maintainability.

Full Changelog: https://github.com/CombustionToolbox/combustion_toolbox/compare/v1.1.3...v1.2.0