Determining Brown's Characteristic Curves Using Molecular Simulation.

Area of Science:

• Thermodynamics
• Fluid Mechanics
• Computational Chemistry

Background:

• Brown's characteristic curves are essential for fluid thermodynamic models but lack experimental data.
• Existing methods for determining these curves are limited or not experimentally validated.

Purpose of the Study:

• To develop a rigorous and generalized method for determining Brown's characteristic curves using molecular simulation.
• To compare different simulation routes to identify the most favorable approach for curve determination.
• To provide a computational procedure and code for practical application.

Main Methods:

• Developed a generalized method based on molecular simulation.
• Compared multiple thermodynamically equivalent definitions and simulation routes.
• Combined molecular simulation, molecular-based equation of state, and second virial coefficient evaluation.
• Tested the method on Lennard-Jones fluid and real substances (toluene, methane, ethane, propane, ethanol).

Main Results:

• Successfully developed and validated a robust computational procedure for determining Brown's characteristic curves.
• Identified the most favorable simulation routes for each characteristic curve.
• Demonstrated accurate results for both model and real fluid systems.
• Presented a computer code implementation for the developed method.

Conclusions:

• The novel molecular simulation-based method provides accurate and reliable data for Brown's characteristic curves.
• This work bridges the gap between theoretical models and experimental validation for fluid thermodynamics.
• The presented computational procedure and code offer a practical tool for researchers and engineers.