Undergraduate Thermodynamics Research Articles

Hands-on engineering design in an undergraduate thermodynamics learning context

Hands-on engineering design is a critical element of quality engineering education commonly featured in the first and last year of undergraduate programs. Technical science and engineering coursework dominate the sophomore and junior year, often with fewer hands-on design experiences. We sought to mitigate this by integrating a hands-on engineering design project into a second-year thermodynamics-focused course for mechanical engineering students. We iterated on a heat-to-work device design project developed by Shepard and Hoxie to make it more open-ended, and to introduce a ‘who’ and a ‘why’ into the project by having students design devices to help hypothetical users accomplish tasks. We analyzed student reflections about the project using an inductive thematic approach. Our results indicate that the project was challenging; students consistently described experiencing failures. Most students were eventually able to succeed in the project using a combination of design iteration, risk-taking, and adaptation. They articulated growth in engineering design capabilities (including the valuation of simplicity in designs, brainstorming, applied learning, and time management), and increases in confidence (including takeaways about the importance of self-trust and intuition). In this paper, we present the revised project design and findings from its implementation using student and instructor reflections, and suggestions about how it could be implemented in thermodynamics courses for other mechanical engineering programs.

The utility of mechanical objects: Aiding students' learning of abstract and difficult engineering concepts

AbstractBackgroundUndergraduate students consistently struggle with mastering concepts related to thermodynamics. Prior work has shown that haptic technology and intensive hands‐on workshops help improve learning outcomes relative to traditional lecture‐based thermodynamics instruction. The current study takes a more feasible approach to improving thermal understanding by incorporating simple mechanical objects into individual problem‐solving exercises.Purpose/HypothesesThis study tests the impact of simple mechanical objects on learning outcomes (specifically, problem‐solving performance and conceptual understanding) for third‐year undergraduate engineering students in a thermodynamics course across a semester.Design/MethodDuring the semester, 119 engineering students in two sections of an undergraduate thermodynamics course completed three 15‐min, self‐guided problem‐solving tasks, one section without and the other with a simple and relevant physical object. Performance on the tasks and improvements in thermodynamics comprehension (measured via Thermal and Transport Concept Inventory scores) were compared between the two sections.ResultsStudents who had a simple, relevant object available to solve three thermodynamics problems consistently outperformed their counterparts without objects, although only to statistical significance when examining the simple effects for the third problem. At the end of the semester, students who had completed the tasks with the objects displayed significantly greater improvements in thermodynamics comprehension than their peers without the relevant object. Higher mechanical aptitude facilitated the beneficial effect of object availability on comprehension improvements.ConclusionFindings suggest that the incorporation of simple mechanical objects into active learning exercises in thermodynamics curricula could facilitate student learning in thermodynamics and potentially other abstract domains.

Revisiting the Clausius/Clapeyron Equation and the Cause of Linearity

In general, for an organic compound a plot of the log vapor pressure versus inverse temperature is linear over a wide temperature range. This however can lead to a point of confusion in an undergraduate thermodynamics course. This linear behavior is typically explained using the Clausius/Clapeyron equation. That is, starting with the Clapeyron equation one first assumes (1) that the change in compressibility upon vaporization is approximately 1, or equivalently that the vapor phase may be treated as an ideal gas where the molar volume of the vapor is much greater than that of the liquid, which may be assumed negligible. And second (2), that the enthalpy of vaporization is constant. While the resulting linear behavior is captured, the underlying assumptions are not applicable over the wide range of temperatures of interest. Here we discuss the shortcomings of the conventional explanation of the Clausius/Clapeyron equation. We further demonstrate that a simple solution is to instead assume that the enthalpy of vaporization relative to the change in compressibility upon vaporization is constant. We provide a series of examples and MATLAB code that can be used in an undergraduate thermodynamics course.

Thermodynamic Analysis for Industrial Refrigeration Systems

The vapor compression cycle (VCC) underpins the vast majority of refrigeration systems throughout the world. Most undergraduate thermodynamics courses cover the VCC, albeit in a cursory fashion. This book is designed to offer an in-depth look at the analysis, design and operation of large-scale industrial ammonia-based refrigeration systems. An important feature of this work is a treatment of computer-aided analysis using CoolProp, an open source resource for evaluating thermodynamic properties. CoolProp can be incorporated into a large number of common computational platforms including Microsfot Excel, Python, and Matlab, all of which are covered in this book.

Thermodynamic identities with sunray diagrams

One of the hurdles in teaching undergraduate thermodynamics is a plethora of complicated partial derivative identities. Students suffer from difficulties in deriving, justifying, or interpreting the identities, misconceptions about partial derivatives, and a lack of in-depth understanding of the meanings of identities. We propose a novel diagrammatic method for the calculus of differentials and partial derivatives called the ‘sunray diagram’ that resolves the difficulties above. The sunray diagram technique relates a partial derivative with ‘arrow sliding’, which enables an aesthetic and intuitive manipulation of partial derivative expressions in the form of successive arrow slidings. Furthermore, the sunray diagram is more than an ad hoc or abstract machinery but is based on the symplectic structure of thermodynamics; the sunray diagram admits a direct physical interpretation on the P–V (or T–S) plane. We elaborate on such physical semantics of the sunray diagram by taking Maxwell’s approach to the geometry of thermodynamic structures—reinterpreted in terms of differential geometry—as a reference point. We anticipate that our discussion introduces the geometry of thermodynamics to learners and enriches the graphical pedagogy in physics education.

Use of a smartphone-based Student Response System in large active-learning Chemical Engineering Thermodynamics classrooms

Smartphones are a promising tool as student response systems (SRS) for interactive teaching due to their widespread diffusion. Here, the main purpose is to assess the efficacy of smartphone-based SRS in large classroom settings of undergraduate Thermodynamics, as representative of engineering courses requiring high-level cognitive skills for problem solving. Four sets of multiple-choice questions were presented during the course. Overall, the results refer to 1055 students between control and SRS classes, each corresponding to a3 years period.One of the main results of this work is the strong linear correlation between the average questionnaire score and the final exam grade (R2 = 0.91). A similar correlation, although with a lower value of R2, is already found in the first questionnaire, thus showing the SRS high predictive power of class performance. The results of this study provide guidance for a quantitative use of smartphone-based SRS in teaching basic disciplines. The SRS monitoring capability allows early detection of struggling students, thus paving the way to personalized tutoring and improved student engagement in active learning practices. This approach is especially important in emergency situations, such as the SARS-Cov-2 pandemic, when distance learning is widely adopted, and remote interactive tools are highly needed.

Redesigning a commercial combined cycle in an undergraduate thermodynamics course: Connecting theory to practical cycle design

Due to various reasons, the concepts of thermodynamics are not easy to grasp for undergraduate students. One of the major reasons is that the students are mostly unfamiliar with the thermodynamics devices discussed in the courses. Offering courses with experiments is an effective approach to solve this issue. However, it is not practical or possible for universities to own devices that operate at high temperatures and with high pressure fluids. With the cooperation of a nearby electric company, undergraduate students of a thermodynamics course from the Department of Mechanical Engineering measured thermal performances of a commercial combined cycle and its sub-systems at the President University. After learning about the theory of thermal cycles, the students analyzed the thermal performances of actual thermodynamics cycles. Subsequently, they analyzed the thermal efficiency improvements when reheating or regeneration is applied to the simple Rankine cycle in the combined cycle. At the end of the course, the students gave presentations before the electric company’s management and engineering personnel, akin to professional engineers. This course is structured to familiarize undergraduate students with thermodynamics cycles and devices.

The computational study of heat conduction in laboratory using Crank-Nicolson finite difference method

The main propose of this research is to study the heat conduction of an aluminium metal bar in an undergraduate thermodynamics laboratory by using the Crank-Nicolson scheme of finite difference method. Heat conduction was simulated to find the thermal conductivity and was compared with the data obtained from the experiment and theory. In the performed boundary and initial conditions, it was found that the predicted thermal conductivity from the simulation was in agreement with those from the theory, however, it was slightly different from the experiment. These results can be used to improve method to find the thermal conductivity in the laboratory more accurately in the laboratory. Besides, these computational approaches can be an optional teaching method for studying thermal conduction for undergraduates, especially for a laboratory that has limited instruments.

Coefficient of performance of Stirling refrigerators

Stirling coolers transfer heat in or out of the working fluid during all four stages of their operation, and their coefficient of performance depends on whether the non-isothermal heat exchanges are performed reversibly or irreversibly. Both of these possibilities can in principle be arranged. Notably, if the working fluid is an ideal gas, the input of energy in the form of heat during one isochoric step is equal in magnitude to the output during the other isochoric step in the cycle. The theoretical performance of the fridge can then attain the reversible Carnot limit if a regenerator is used, which is a high heat capacity material through which the gas flows. Various Stirling refrigerator configurations are analysed in this article at a level of presentation suitable for an introductory undergraduate thermodynamics course.

An air-standard finite-time heat addition Otto engine model

A classical thermodynamic model for spark-ignited internal combustion engine simulation in which the heat addition process that takes a finite amount of time to complete is presented along with an illustrative parameter sensibility case study. The model accounts for all air-standard Otto cycle parameters, as well as crank-connecting rod mechanism, ignition timing, engine operating speed, and cumulative heat release history parameters. The model is particularly suitable for engineering undergraduate education, as it preserves most of the air-standard assumptions, while being able to reproduce real engine traits, such as the decay of maximum pressure, power, and thermal efficiency at higher engine operating speeds. In terms of complexity, the resulting finite-time heat addition Otto cycle sits between the classical air-standard Otto cycle and the more involved air–fuel Otto cycle, that are usually introduced on more advanced mechanical engineering courses, and allows students to perform engine parameter sensibility studies using only classical, single phase, pure substance, undergraduate engineering thermodynamics.

A point of view on Otto cycle approach specific for an undergraduate thermodynamics course in CMU

This paper refers to the description of the way in which can be presented to future marine engineers the analyzis of the performance of an Otto cycle, in a manner which is beyond the classic approach of the course of thermodynamics in Constanta Maritime University. The conventional course of thermodynamics is dealing with the topic of performance analysis of the cycle of the internal combustion engine with isochoric combustion for the situation in which the working medium is treated as such a perfect gas. This type of approach is viable only when are considered relatively small temperature differences. But this is the situation when specific heats are seen as constant. Instead, the practical experience has shown that small temperature differences are not viable, resulting the need for variable specific heat evaluation. The presentation bellow is available for the adiabatic exponent written as a liniar function depending on temperature. In the section of this paper dedicated to methods and materials, the situation in which the specific heat is taken as constant is not neglected, additionaly being given the algorithm for variable specific heat.For the both cases it is given the way in which it is assessed the work output. The calculus is based on the cycle shown in temperature- entropy diagram, in which are also indicated the irreversible adiabatic compression and expansion. The experience achieved after understanding this theory will allow to future professionals to deal successfully with the design practice of internal combustion engines.

Student opinions and perceptions of undergraduate thermodynamics courses in engineering

Thermodynamics is a fundamental foundation of all engineering disciplines. A vast majority of engineering undergraduate programmes contain one or more courses on thermodynamics, and many engineers use thermodynamics every day to analyse or design energy systems. However, there is extensive anecdotal evidence as well as a wide range of published literature indicating that students often struggle to understand thermodynamic principles. In an effort to understand students' attitudes and perception of thermodynamics, including their expectations, experience and frustrations, an investigation was conducted. Following a review of the literature on the teaching and learning of thermodynamics in engineering, a survey questionnaire was developed and administered to close to a 1000 students in 17 thermodynamics classes at 13 universities in 7 countries. Survey results were analysed using statistical methods. This paper presents the findings of this investigation.

Beyond Clausius–Clapeyron: Determining the second derivative of a first-order phase transition line

We obtain an expression for the second derivative of the line in a PT diagram denoting a first-order phase transition for a pure hydrostatic system. Our result goes beyond the classical Clausius–Clapeyron equation, which provides only the first derivative of the pressure with respect to the temperature along the transition line. We present two pedagogical derivations suitable for an undergraduate thermodynamics class; the first one uses derivatives of the entropy while the second one uses derivatives of the enthalpy. The final expression for the second derivative involves only standard thermodynamic quantities such as the specific heats, the isothermal compressibilities, and the coefficients of thermal expansion of the two phases at the transition line. As an illustration, we compute the second derivatives of the freezing and vaporization lines of water at atmospheric pressure, and show that at this pressure the freezing line is concave down (negative second derivative) while the vaporization line is concave up (positive second derivative).

Measuring the Specific Heat of Metals by Cooling

Three in one? Yes, three standard undergraduate thermodynamics experiments in one, not an oval can of lubricating oil. Previously it has been shown that the PASCO scientific1 apparatus for measuring coefficients of thermal expansion of metals can also be used to illustrate Newton's law of cooling in the same experiment.2 Now it will be shown that by cooling geometrically identical metallic samples and measuring their surface temperature change as a function of time, the specific heat of metals can be found by the method of comparison. This technique is simple to implement using the PASCO equipment for measuring the coefficients of thermal expansion of metals. A slight variation on this method was used in the Moscow State University students' laboratory for measuring temperature dependence of specific heat of copper over a large temperature range. As a result of this method, three experiments can be undertaken simultaneously to measure: 1) the coefficient of thermal expansion (α); 2) the time constant in Newton's law of cooling (H); and 3) the specific heatof metals (C).

Undergraduate Thermodynamics Courses

Undergraduate Thermodynamics Courses

Quantitative experiments on supersaturated solutions for the undergraduate thermodynamics laboratory

Quantitative experiments on supersaturated solutions are presented. They serve to introduce topics such as the solubility curve and irreversible phase transitions. Experimental results are analysed with the aid of Hess's law. These kind of experiments, which in the present case employed sodium acetate trihydrate, may be chosen as a student's project in experimental thermodynamics.

Assessing the Given–Find–Solution Method in an Undergraduate Thermodynamics Course

This paper describes the given–find–solution method as a general approach to solving engineering problems. An in-classroom study was conducted to provide evidence of its effectiveness in increasing, students' problem-solving proficiency. The target course was an undergraduate service thermodynamics course taught at Montana State University. Results indicate that the given—find—solution method seems to be effective for most students. The implications for assessment and methodological improvements are discussed.

Study of Polymer Glasses by Modulated Differential Scanning Calorimetry in the Undergraduate Physical Chemistry Laboratory

Recent technological advances in thermal analysis present educational opportunities. In particular, modulated differential scanning calorimetry (MDSC) can be used to contrast reversing and nonreversing processes in practical laboratory experiments. The introduction of these concepts elucidates the relationship between experimental timescales and reversibility. The latter is a key concept of undergraduate thermodynamics theory that deserves reinforcement. In this paper, the theory and application of MDSC to problems of current interest is outlined with special emphasis on the contrast between crystallization and vitrification. Glass formation deserves greater emphasis in the undergraduate curriculum. Glass transitions are increasingly recognized as an important aspect of materials properties and dynamics in fields ranging from polymer science to protein folding. The example chosen for study is a comparison of polyethylene glycol and atactic polypropylene glycol. The experiment is easily performed in a typi...

Advanced Thermodynamics Engineering. Computational Mechanics and Applied Analysis Series

7R52. Advanced Thermodynamics Engineering. Computational Mechanics and Applied Analysis Series. - K Annamalai (Dept of Mech Eng, Texas A&M, College Station TX 77843) and IK Puri (Dept of Mech Eng, Univ of Illinois, Chicago IL). CRC Press LLC, Boca Raton FL. 2002. 786 pp. ISBN 0-8493-2553-5. $89.95. Reviewed by L Byrd (ARFL/VASM, WPAFB, 2790 D St, Dayton OH 45433-7402).This book is best suited as a textbook for students that have had two semesters of thermodynamics. Many of the topics can also be found in introductory texts, but will be somewhat lightly studied in a standard two-class series. There are a large number of topics that are not covered in the standard mechanical engineering sequence, although they come up in combustion or the chemical engineers sequence. One advantage of this book is that the material is in one text, and so it can act as a reference for practicing engineers. An extensive nomenclature list is included which is fortunate because the authors tend to use a lot of symbols and acronyms. It also makes it easier to read just the section of interest rather than starting at the beginning and reading material that is irrelevant to define the variables. A quick outline of the book reveals: Analysis of multi-component systems is introduced early in the text and carried through as needed. The introduction to statistical thermodynamics is brief due to the broad range of topics covered. The third and fourth chapters discuss first- and second-law analysis, entropy generation, and availability analysis, while Chapters 6 and 7 cover equations of state and pure fluids. Much of this is covered in undergraduate texts, but repeating it helps introduce the advanced material. The authors include numerous examples, and this material would be useful in design using entropy generation minimization. The nomenclature used in the European literature is introduced which is helpful when reviewing international texts. Chapter 5 is a short one describing thermodynamics in terms of four postulates rather than laws. It deals largely with use of the Legendre transform of the internal energy formulation of the equation of state. The remainder of the book deals with topics generally found in chemical engineering thermodynamics. Chapters 8 and 9 cover non-reacting mixtures. Chapter 11 principally introduces the thermodynamics of combustion and chapters 11–13 cover chemically reacting systems. One addition that would fit in with the aim of the text would be more coverage of psychrometrics. Another would be software to replace the tables of material property data found at the back of the text. The main criticism this reviewer has for the text is the large number of publishing errors. This reviewer estimates there are several hundred changes that should have been made before the book was printed. It should be stated that, except for the figures, the vast majority of these changes are minor. Examples are inconsistent subscripting of variables, changes in font size, or repeated words. By far, the biggest problem is the horrendous quality of the figures. In many figures, text was left out or partially obscured or just unreadable. In a few cases, the usefulness of the figure was totally negated. The graphics were of low quality. A comparison of the figures with those in the text from this reviewer’s undergraduate thermodynamics class, which was written over 30 years ago, shows that a great deal of improvement is possible. Writing a text is hard work, and for the authors to catch typing errors is difficult because the mind corrects for mistakes that occur. This reviewer will keep this book on his shelf and anticipates using it because the broad range of topics covered and the numerous examples given make it a good reference text. What this reviewer would really like to have is the corrected version because Advanced Thermodynamics Engineering could evolve into an excellent text.

Practising Helps: Thermodynamics, History, and Experiment

Teaching undergraduate students thermodynamics is quite often reduced to a mere mathematical treatment of Gedankenexperimente based on the two abstract fundamental postulates of thermodynamics. In a course given at the University of Oldenburg we attempt to remedy the deficiencies of such courses. Our aims are twofold: First we try to take the historical context into consideration in order to illustrate the importance of the socio-economical development for the scientific progress. Secondly, we include experimental work into the course. Here, we use replications of past experiments. In this paper I will describe the course and compare it, firstly, with two ``classical'' approaches represented by the textbooks of H.B. Callen and F. Reif; secondly, I will point out the advantages the use of replications have compared to ``modern adaptions''.