TITLE:
Simplified Coarse-Grained Dynamic Model for Real Gases
AUTHORS:
Panagis G. Papadopoulos, Christopher G. Koutitas, Yannis N. Dimitropoulos, Elias C. Aifantis
KEYWORDS:
Real Gases, Coarse-Grained Molecular Dynamics, Particles Volume, Inter-Particle Attractive Forces, Lennard-Jones Curve, Step-by-Step Time Integration Algorithm, Condensation, Critical Point, Iso-Kinetic Energy Curves, Iso-Therms, Van der Waals Model
JOURNAL NAME:
Open Journal of Physical Chemistry,
Vol.7 No.2,
May
16,
2017
ABSTRACT: A simplified model is proposed for an easy understanding of the coarse-grained technique and for achieving a first approximation to the behavior of gases. A mole of a gas substance, within a cubic container, is represented by six particles symmetrically moving. The impacts of particles on container walls, the inter-particle collisions, as well as the volume of particles and the inter-particle attractive forces, obeying a Lennard-Jones curve, are taken into account. Thanks to the symmetry, the problem is reduced to the nonlinear dynamic analysis of a SDOF oscillator, which is numerically solved by a step-by-step time integration algorithm. Five applications of proposed model, on Carbon Dioxide, are presented: 1) Ideal gas in STP conditions. 2) Real gas in STP conditions. 3) Condensation for small molar volume. 4) Critical point. 5) Iso-kinetic energy curves and iso-therms in the critical point region. Results of the proposed model are compared with test data and results of the Van der Waals model for real gases.