Hybrid Vehicle Design Challenge
Hybrid engine schematic.Copyright 2004 Welleman at nl.wikipedia, Wikimedia Commons http://commons.wikimedia.org/wiki/File:Hybrid_engine.jpg
The design uses a contextually based "Challenge" followed by a sequence of instruction in which students first offer initial predictions ("Generate Ideas") and then gather information from multiple sources ("Multiple Perspectives"). This is followed by "Research and Revise" as students integrate and extend their knowledge through a variety of learning activities. The cycle concludes with formative ("Test Your Mettle") and summative ("Go Public") assessments that lead the student towards answering the Challenge question. See the unit overview section for the progression of the legacy cycle through the unit. Research and ideas behind this way of learning may be found in How People Learn, (Bransford, Brown & Cocking, National Academy Press, 2000). View the entire text at https://www.nap.edu/catalog/9853/how-people-learn-brain-mind-experience-and-school-expanded-edition.
The legacy cycle is similar to the engineering design process in that they both involve identifying a societal need, combining science and math to develop solutions, and using the research conclusions to design a clear conceived solution to the original challenge. Though both the engineering design process and legacy cycle depend on a correct and accurate solution, each focuses particularly on how the solution is devised and presented. See an overview of the engineering design process at https://en.wikipedia.org/wiki/Engineering_design_process.
In Lesson 1, students are presented with a Challenge Question: "The rising price of gasoline has many effects on the US economy and the environment. You have been contracted by an engineering firm to help design a physical energy storage system for a new hybrid vehicle for Nissan. How would you go about solving this problem? What information would you consider to be important to know? You make a small prototype of your idea and make a sales pitch to Nissan at the end of the unit."
Students begin by Generating Ideas in a journal, answering questions such as, "How does the internal combustion engine currently work?" and "How do current hybrids work?" and "What other forms of energy are available?"
Lesson 2 moves into the Research and Revise phase to focus on the conservation of energy solely between gravitational potential energy and kinetic energy. Students start out with a virtual laboratory, and then move into the notes and working of problems as a group. A few questions are given as homework. A dry lab that focuses on the kinetic and potential energies on a roller coaster concludes the lesson in the Test Your Mettle phase of the legacy cycle.
In Lesson 3, as part of the Research and Revise step students investigate potential energy held within springs. Class begins with a video of either spring shoes or bungee jumping. Students then move on into notes and problems as a group. A few questions are given as homework. The Test Your Mettle section concludes the lesson and includes a dry lab that involves pogo sticks that to solidify the concepts of spring potential energy, kinetic energy, and gravitational energy, as well as conservation of energy.
In Lesson 4, students conclude the Research and Revise step of the legacy cycle, as they investigate different forms of hybrid engines as well as take a brief look at the different forms of potential energy.
In Activity 4 (Energy Storage Derby and Proposal), students finish the legacy cycle with the Go Public phase. A design problem is given to the students to design and construct a small-scale vehicle to participate in a derby. To be considered for a complete project, vehicles must complete a 10-meter run in the hallway. Submissions are ranked on performance in three areas: 1) vehicle weight, 2) unloaded time, and 3) time with a 250 g load. Students then make sales pitches for their ideas and prototypes to be considered in Nissan's next design.
Alternative energy sources, particularly within the realm of transportation, are a hot topic in the scientific and engineering communities. Achieving a design for a safe and efficient method of capturing the energy given off by a vehicle and transferring it into kinetic energy is of utmost importance. Throughout this unit, students apply the classroom-presented scientific concepts of energy conservation to the real-world problem of designing and implementing a system for energy transformation in vehicles.
