Abstract:

One of the first major courses taken by undergraduate students in the thermal and fluid sciences thread in a mechanical engineering curriculum is Thermodynamics--defined simply as the science of energy. Unlike previous courses taken by students such as Statics, Dynamics and Solid Mechanics which are taught for the most part as formula-based courses, it is the practice sometimes, depending on the instructor, to attempt to wean students from that approach and to introduce a more formalized system of learning and understanding engineering subjects. This approach requires discipline and involves the derivation and demonstration of most of the equations that govern the science of energy. The equations of interest fall into two main categories: definitions such as enthalpy, and those that capture the laws of physics such as the law of energy conservation. In a class of fifty students, one may find more than half of the class resistant to change to the more formalized approach to teaching as they have a hard time moving away from an approach that has been inculcated in them since grade school. Access to internet resources that promote the use of formula-based learning do not help in the process of changing the paradigm.

This paper describes a paradigm that has been used by the author to teach Thermodynamics to first-semester juniors in an undergraduate mechanical engineering curriculum. The pre-requisites for the class are successful completion of Physics I (Work and Heat), Physics II (Electricity and Magnetism), Calculus I and II, and concurrently with Differential Equations. The reason for the change in paradigm from the formula-based approach is to make the students understand that being a good engineer involves more than just putting pieces of ‘Legos’ together and to desist from thinking that the problems of the world are solved from formulas that are available through search engines on the internet. The teaching approach described in this paper is designed to have the students think critically (painful at times), and to guide them through a process in which they can solve end of chapter problems without the need for a formula-sheet in homework assignments or during examinations. To make it fun and enjoyable while learning and understanding the course materials, the first law of thermodynamics and other conservation principles are presented as analogous to the flow of money in a bank account; like the flow of energy through a region of space, an analogy between money and energy is made in which a banking account or a savings booklet is treated as a system/control volume with the application of basic accounting principles. Other innovative aspects of the course to promote understanding and learning are also presented in the paper. Continuing assessment of the new paradigm include a comparison with the performance of the students in assigned work performed in other formula-based classes. Although not all students embrace the new approach, the qualitative and quantitative assessments of the approach presented in the paper show a marked improvement in the learning and understanding of the science of energy. The approach described in the paper can be applied in the teaching, learning, and understanding of other thermal/fluid science classes.

Keywords:

Thermodynamics, basic laws, teaching and learning.