Reconsidering the Foundations of Thermodynamics from an Engineering Perspective (original) (raw)

RESEARCH INTO THE ORIGINS OF ENGINEERING THERMODYNAMICS

This paper draws attention to a series of misconceptions and misstatements regarding the origin and meaning of some of the most basic concepts of engineering thermodynamics. The six examples exhibited in the paper relate to the concepts of reversibility, entropy, mechanical equivalent of the calorie, the first law of thermodynamics for open systems, enthalpy and the Diesel cycle. A complete list of the pioneering references concludes the paper. Obiective The discipline of Engineering Thermodynamics revolves around a relatively large number of good introductory treatments, which-in my view-are all very similar except for certain variations in writing style and graphics quality. It would seem that for generation after generation Engineering Thermodynamics has flowed from one book into the next, essentially unchanged. Today the textbooks describe a seemingly moribund engineering discipline, that is, a subject void of controversy and, most regrettably, references. As students, we are brought in contact with a discipline whose step-by-step innovations seem to have been long forgotten. Traveling back in time to "rediscover" the origins of the discipline is a task tackled only by a curious few. This situation presents a tremendous opportunity for the researcher. I recognized this opportunity four years ago when I began work on a graduate treatise on engineering thermodynamics [1]. In the course of that work I made numerous trips to the Library of Congress, in Washington, DC, where many of the original writings can be located. The many facts and references I discovered are 571

A Novel Sequence of Exposition of Engineering Thermodynamics *

Journal of Energy Resources Technology, 2014

We present the foundations of thermodynamics in a novel sequence in which all basic concepts are defined in terms of well known mechanical ideas. Many definitions are new. The order of introduction of concepts is: system (constituents and parameters); properties; state; energy (without heat and work) and energy balance; classification of states in terms of time evolution; existence of stable equilibrium states; available energy; entropy (without heat and temperature) of any state (equilibrium or not) and entropy balance; properties of stable equilibrium states; temperature in terms of energy and entropy; chemical potentials; pressure; work; heat; applications of balances. This novel sequence not only generalizes the subject of thermodynamics to all systems (large or small) and all states (equilibrium and not equilibrium) but also avoids both the conceptual and definitional difficulties that have been recognized by so many teachers, and the confusion experienced by so many students.

Clausius’ thermodynamics, engineering thermodynamics based on the entropy principle by discarding the energy premise

Thermodynamics is the theory of energy resulted from the conceptual differentiation of caloric, circa 1850-1865, into energy, entropy, and heat (a disorganized form of energy) in terms of the two laws of thermodynamics, the first law and the second law. The theory is often referred to as the Clausius-Kelvin theory as a single theoretical system. In actual fact, it is a blend of Kelvin's contribution and Clausius' contribution. Orthodox engineering thermodynamics is instead an update of the energy physics formulated by Kelvin circa 1850-55 based on the energy premise, which stops short of the conceptual differentiation in the exact sense. It is the Clausius version of the theory that was transformed by Gibbs into Gibbsian thermodynamics, which is the result of the conceptual differentiation. As a result, engineering thermodynamics is a defective theoretical system while Gibbsian thermodynamics is a successful one. This paper makes the case that Clausius' theorem of entropy can be developed for reforming engineering thermodynamics into a coherent system by rejecting the energy premise.

A New Approach to Understanding Engineering Thermodynamics from Its Molecular Basis

AWARDED ASME HONOURS: Engineering Thermodynamics is that engineering science in which students learn to analyze dynamic systems involving energy transformations, particularly where some of the energy is in the form of heat. It is well known that people have difficulty in understanding many of the concepts of thermodynamics; in particular, entropy and its consequences. However, even more widely known concepts such as energy and temperature are not simply defined or explained. Why is this lack of understanding and clarity of definition prevalent in this subject? Older engineering thermodynamics textbooks (often containing the words "heat engines" in the title) had a strong emphasis in their early chapters on the general physical details of thermodynamic equipment such as internal and external combustion engines, gas compressors and refrigeration systems. The working fluid in these systems might expand or contract while heat, work and mass might cross the system boundary. The...

Thermodynamics: The Unique Universal Science

Entropy

Thermodynamics is a physical branch of science that governs the thermal behavior of dynamical systems from those as simple as refrigerators to those as complex as our expanding universe. The laws of thermodynamics involving conservation of energy and nonconservation of entropy are, without a doubt, two of the most useful and general laws in all sciences. The first law of thermodynamics, according to which energy cannot be created or destroyed, merely transformed from one form to another, and the second law of thermodynamics, according to which the usable energy in an adiabatically isolated dynamical system is always diminishing in spite of the fact that energy is conserved, have had an impact far beyond science and engineering. In this paper, we trace the history of thermodynamics from its classical to its postmodern forms, and present a tutorial and didactic exposition of thermodynamics as it pertains to some of the deepest secrets of the universe.

A New Perspective for The Laws of Thermodynamics

Universidad Simón Bolívar, 2024

The main objective of this article is to present the laws of thermodynamics with a new perspective that involves a paradigm shift in the form of reasoning that has traditionally been inductive in nature, now presented with deductive characteristics. The laws are presented at the beginning in the way they are believed to be and then the different components that make them up are described.

Unified view of the Principles of Thermodynamics

Based on ideas of B. Finzi [one of the professors at Milan Politecnico] to be found in a paper published in the "Periodico di Matematiche, serie IV, vol. XIV, 1935", entitled, in Italian, COSA È LA TEMPERATURA (what is the temperature), we present some concepts unifying the 4 Principles of Thermodynamics. The reader can find useful extensions in the papers "The Mathematics of Thermodynamics", and "Addendum to the Mathematics of Thermodynamics". Using the fact that the absolute temperature T is related to the energy of any degree of freedom of a molecule we will show that the 4 Principles of Thermodynamics have a common physical explanation, in terms of T.

The Auxiliary Components of Thermodynamic Theory and Their Nonempirical, Algorithmic Nature

Physics Essays, 2006

Thermodynamic laws are not "equations of motion"; in contrast to the specificity of other fundamental laws of physics, the hallmark of thermodynamic laws is generality. This raises the issue of whether auxiliary assumptions required in applying general thermodynamic laws to particular systems are also of a different nature. Lacking proper understanding of this nature, students of thermodynamics encounter a number of puzzles and misconceptions. A central puzzle is how one makes specific predictions with general laws lacking in specificity. Despite these occasional (but conceptually fundamental) difficulties, it is undeniable that examples of the successful application of thermodynamics abound. This paper argues that all successful applications of thermodynamic laws to particular processes making specific predictions are accompanied by auxiliary components -either explicitly or in tacit form. These are either the usual auxiliary assumptions -or a new kind of auxiliary components, which are idealized (nonempirical) contriving or algorithmic means. This is the radical idea (of the Carnot cycle as an algorithmic process) introduced by Carnot. This central thesis concerning the structure of thermodynamic theory is presented with the support of a good number of evidential examples. In comparison with other physical theories, which are nomothetic sciences, thermodynamic theory reveals its difference in structure and aim as being an atypical nomothetic science with the distinctive hybrid feature of nomothetic sciences and principle-based sciences. Real contriving or algorithmic creations change and evolve with time intrinsically. It is argued that this contriving/historical connection characterizes the nature of engineering knowledge, which is identified as being a historical principle-based science. In comparison to engineering knowledge, biological sciences, it is further suggested, reveal their structural similarity with engineering.