Nanoscale thermal systems in subcritical region

The behavior of a nanoscale fluid system in the subcritical region is investigated using molecular simulation. The fluid used is argon and the intermolecular forces are represented by the Lennard-Jones potential. The simulations show that the phase change in a nanoscale system becomes continuous as opposed to the constant temperature and constant pressure phase change for a macroscale system. Then nonlinear curve fitting was performed using two cubic equations to obtain a representation of the simulation data. The continuous phase change behavior predicted by the molecular simulation is verified by using an approximate analytical analysis. A cubical system is defined for five different configurations based on the minimization of the interfacial surface area. These systems are then analyzed to define their thermodynamic behavior by using a technique to minimize the Helmholtz free energy. It is also shown how this continuous phase change alters the behavior of nanoscale thermal systems in subcritical thermodynamic cycles. A nanoscale vapor heat engine shows a lower efficiency than the macroscale vapor heat engine and the coefficient of performance for a nanoscale refrigeration cycle is higher than that for a macroscale refrigeration cycle.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Engineering

Grantor

Rice University

Year dc:date.issued

2001

Author dc:creator

• Hos, Pascal

Advisor dc:contributor.advisor

• Bayazitoglu, Yildiz

• Mechanical engineering

Statement dc:rights

• Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.

Language dc:language.iso

eng

Handle dc:identifier.uri

https://hdl.handle.net/1911/17976

OAI identifier oai:identifier

oai:repository.rice.edu:1911/17976