THERMODYNAMICS FROM A FEW DYNAMIC PARTICLES RAISES QUESTIONS AS TO HOW TEMPERATURE AND ENTROPY SHOULD BE PERCEIVED AND DEFINED

摘要

In a recently developed simple particle mechanics model, in which a single particle represents the working fluid, (gas) in a heat engine, (exemplified by a piston engine) a new approach was outlined for the teaching of concepts to thermodynamic students. By mechanics reasoning, a model was developed that demonstrates the connection between the Carnot efficiency limitation of heat engines, and the Kelvin-Planck statement of Second Law, requiring only the truth of the Clausius statement. In a second paper the model was extended to introduce entropy. The particle's entropy was defined as a function of its kinetic energy, and the space that it occupies, that is analogous to that normally found in classical macroscopic analyses. In this paper, questions are raised and addressed: How should temperature and entropy be perceived and defined? Should temperature be proportional to average (molecular) translational kinetic energy and should entropy be dimensionless?