⚖️ chem-eq-calculator - Chemical Equilibrium Calculator

Professional thermodynamic analysis software with NASA CEA2 integration

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🚀 Installation

pip install chem-eq-calculator

Run the application

chem-eq-calculator

Or from Python:

from chem-eq-calculator import CEACalculator

calc = CEACalculator()
calc.set_oxidizer("NH4ClO4(I)", 298.0, 72.0)
calc.set_fuel("HTPB", 298.0, 18.0)
calc.set_conditions(pc=50.0, of_ratio=2.5, ae_at=10.0)
result = calc.run()
print(f"Isp: {result.isp_ms:.0f} m/s")

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🔬 Overview

Chemical Equilibrium Calculator (chem-eq-calculator) is a professional-grade desktop application for thermodynamic equilibrium calculations in chemical systems. Built with a modular MVC architecture, it provides precise equilibrium composition analysis, thermodynamic property calculations, and comprehensive performance evaluation.

The software integrates with NASA's CEA2 for high-precision calculations while maintaining a robust fallback ideal gas calculator.

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✨ Features

Category	Features
Equilibrium Calculations	Complex multi-species chemical equilibrium analysis
Thermodynamic Properties	Temperature, pressure, enthalpy, entropy computations
Nozzle Design	Isentropic flow analysis and geometric optimization
Batch Processing	Parametric sweeps and sensitivity analysis
Visualization	Interactive plots, radar charts, and performance graphs
User-Defined Reactants	Custom species with atomic composition
Multi-language	English and French interfaces

Species Database

• 129 Oxidizers - Complete NASA CEA2 oxidizer list
• 397 Fuels - Extensive fuel database including hydrocarbons, metals, and hydrides
• 70+ Elements - Periodic table for custom composition

Analysis Tools (25+)

• Nozzle Designer, Chamber Sizer, Contraction Ratio
• Heat Transfer (Bartz), Regenerative Cooling, Instability Predictor
• Delta-V Calculator, Orbit Insertion, Staging Optimiser
• Sensitivity Analysis, Design of Experiments, Composition vs T
• LaTeX Generator, Python Script, Unit Converter

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📋 Requirements

• Python 3.11 or higher
• PySide6 >= 6.6.0
• matplotlib >= 3.7.0
• numpy >= 1.24.0
• pandas >= 2.0.0
• qtawesome >= 1.3.0

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🎯 Quick Start

Basic Calculation Workflow

# Run the GUI application
chem-eq-calculator

Example Formulation

Parameter	Value
Oxidizer	NH₄ClO₄(I)
Oxidizer Temp	298.0 K
Oxidizer Wt	72.0 %
Fuel	HTPB
Fuel Temp	298.0 K
Fuel Wt	18.0 %
Chamber Pressure	50.0 bar
O/F Ratio	2.5
Area Ratio	10.0

Expected Results

Metric	Value
Specific Impulse (Isp)	~250 s (2450 m/s)
Characteristic Velocity (C*)	~1580 m/s
Thrust Coefficient (Cf)	1.55-1.65
Chamber Temperature (Tc)	~3300 K

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🛰️ NASA CEA2 Integration

For high-precision calculations, install NASA CEA2:

pip install cea

Then configure paths in the application Settings (Ctrl+,).

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📖 Keyboard Shortcuts

Action	Shortcut
Calculate	Ctrl+R
Validate	Ctrl+Shift+V
Add Session	Ctrl+T
Load .inp	Ctrl+O
Save .inp	Ctrl+S
Export CSV	Ctrl+E
Open Settings	Ctrl+,

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🐛 Troubleshooting

Issue	Solution
ModuleNotFoundError	Run pip install chem-eq-calculator --force-reinstall
No species in dropdown	Verify databasecea.txt exists
Plots not displaying	Install matplotlib: pip install matplotlib
FCEA2 execution error	Configure CEA2 paths in Settings

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📄 License

chem-eq-calculator - Chemical Equilibrium Calculator
Copyright (C) 2026 Oukil Khaled Ibn Elwalid

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

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👨‍💻 Author

Oukil Khaled Ibn Elwalid

• GitHub: @khadev
• Email: oukil.khaled@gmail.com

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