Date of Award

Fall 2020

Document Type

Dissertation - Restricted

Degree Name

Doctor of Philosophy (PhD)


Mechanical Engineering

First Advisor

Gaggioli, R. A.

Second Advisor

Dunbar, W. R.

Third Advisor

Nigro, N. J.


This document springs forth from the application of the Second Law of Thermodynamics to a variety of problems, with the ultimate goals of both improving the design process and the methods by which new technologies might be conceived and developed. It is divided into three parts, attacking basic thermal science, modeling and finally, design. The first two parts discuss topics that are ultimately relevant to the third. One can think of each three as a layer; basic science forms the foundation of what we do as engineers. Modeling is how we apply this science to real problems. Design (and/or analysis) moves the exercise from the mathematical to the physical. Extremization Principles The understanding of science at a basic level is necessity for the engineer. Without this understanding, he would be unable to mathematically model a system, and he would not be properly guided through the creative process of original design. The first part of this dissertation, Extremization Principles applied to thermodynamics, contains several "case studies", where observations are made about the minimization and maximization of the rate and total entropy production in a variety of processes. These case studies were preliminary activities in an attempt to find a single "equation of motion" for Thermodynamics, especially a variational principle similar to Hamilton's principle. This attempt is, at the time of this writing, unsuccessful except for certain specialized cases (see Appendix C). The majority of these "case studies" are systems whose solutions are well known; in several of them others have already observed the entropy minimization or maximization. Nonetheless, before work proceeded on a variational principle it was deemed wise to revisit these cases, especially from an available energy perspective...



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