Using student-faculty collaborative lectures to teach high level hydrodynamics concepts

Abstract

Introduction to engineering courses are increasingly team-based and project-based, with student teams designing and building real-world things. A popular project for introductory courses is remotely operated vehicles (ROVs). Our section of an intro to engineering class at a large Midwestern research university uses ROVs because they are fundamentally interdisciplinary: a successful design includes elements of mechanical engineering, electrical engineering, computer science, naval architecture, marine engineering, and others. However, over the years we have observed that students continued to struggle with an early understanding of the forces and moments that impact how ROVs move through the water - in other words, hydrodynamics. This lack of hydrodynamic understanding leads them to design vehicles that are frustrating to drive because they are not hydrodynamically stable. Our objective was to give students a high-level understanding of basic hydrodynamics concepts (drag, stability, free body diagrams) such that their initial design choices are better informed. However, hydrodynamics is a complex and nuanced field of study, and teaching even high-level hydrodynamics concepts is challenging at best. A traditional lecture format teaching a formal introduction to hydrodynamics is not an option because our students do not yet have the background math and science knowledge necessary to understand the equations used in such an introduction. Using pure observation to convey high level concepts through experiential learning is ideal, and we do this in our lab sections, but students need to have some conceptual preparation before they do their lab-based learning. Because we were moving to an active learning format in which students work in their teams the majority of the class meeting time, we decided to take advantage of the small groups to create interactive lectures on hydrodynamics to prepare students for their labs on hydrodynamics. The collaborative lectures on hydrodynamics start with a scaffolded Google slides presentation. Students make a copy of the presentation and share it with their teammates. The presentation uses pictures and diagrams to create a type of experiential learning in lieu of something like a recirculating water channel. The instructor presents the slides, but there are many incomplete sections. Each incomplete section is a time for the student teams to discuss a picture, a concept, or a linked video demonstration; come to a consensus on their interpretations of the concepts; or complete a quick example of each concept. A key component of the interactive lecture is that no solution slides are provided. The teams must work through the calculations or reflections to gain a complete set of slides. This forces all students to engage in the lecture. Answers are shared out in the larger group and the instructor guides the discussion of the answers so as to ensure a common understanding of the concepts. Our initial assessment shows a marked improvement in student understanding of the relevant hydrodynamics concepts necessary to designing an underwater vehicle. Students are able to converse more knowledgeably on hydrodynamics, and the ROV designs are more thoughtful and reasoned with respect to hydrodynamics. We believe that this approach of collaborative lectures with small groups will be beneficial to others needing to teach high-level concepts to students who do not yet have the background knowledge required for more formal teaching.