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Updated: Aug 8, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Direct Monte Carlo simulation methods for nonreacting and reacting systems at fixed total internal energy or enthalpy
William R Smith1, Martin Lísal
1Department of Mathematics and Statistics, and School of Engineering, College of Physical and Engineering Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada. wsmith@gibbs.mathstat.uoguelph.ca
Abstract:
A Monte Carlo computer simulation method is presented for directly performing property predictions for fluid systems at fixed total internal energy, U, or enthalpy, H, using a molecular-level system model. The method is applicable to both nonreacting and reacting systems. Potential applications are to (1) adiabatic flash (Joule-Thomson expansion) calculations for nonreacting pure fluids and mixtures at fixed (H,P), where P is the pressure; and (2) adiabatic (flame-temperature) calculations at fixed (U,V) or (H,P), where V is the system volume. The details of the method are presented. The method is compared with existing related simulation methodologies for nonreacting systems, one of which addresses the problem involving fixing portions of U or of H, and one of which solves the problem at fixed H considered here by means of an indirect approach. We illustrate the method by an adiabatic calculation involving the ammonia synthesis reaction.
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