A Visual Approach to Teaching Properties of Water in Engineering Thermodynamics

Overcoming the challenge of using the steam tables can be considered a rite of passage in undergraduate thermodynamics courses. Students often circumvent the use of steam tables and resort to simpler digital alternatives to retrieve properties. In fact, the steam tables and their digital relatives that supply numeric property values fail to reinforce the fundamentals; namely, how state properties are related to each other. Supplying state properties without context adds to the abstractness of water properties which lack a simple equation of state. Instead, research has demonstrated that replacing the steam tables with property charts can greatly improve student’s ability to visualize property relationships and facilitate the creation of a mental model of the complicated equation of state for water. Recognizing these results, the traditional use of the steam tables for property retrieval was entirely replaced by property charts for an engineering thermodynamics course. To leverage the highly visual nature of the property charts, animated videos and related multimedia resources were produced and used in a flipped classroom setting for instruction. This new implementation greatly reduced instructional load and allowed deeper engagement with the concepts taught. The new instructional practice was evaluated by a controlled impact study and student feedback. The evaluation study showed that the students who used property charts as their primary reference were significantly better at predicting water property trends when compared to students who relied on the steam tables accompanied by property chart sketches. When surveyed, students favored property charts and the supplementary videos for their ability to visually convey the complex relationships. The results support existing research and make a strong case for revising thermodynamics pedagogy within engineering. By embedding an intuitive and evidence-based approach to teach the engineering fundamentals, educators can ensure that students are better equipped for professional practice.