Saturday, October 12, 2013

A Thermodynamics Class Project

In my graduate thermodynamics class last year we did a semester-long project developing a computer model of an internal combustion, spark ignition engine.  We started with a simple Otto cycle and through the course of the semester added more realistic effects until by the end of the semester we had a fairly reasonable computer model for an engine.
The motivation for this approach to the class was to provide a coherent framework for a variety of advanced thermodynamic topics that could be covered in parallel with the project development.  This project also lent itself to an incremental, building block approach.  We started with a cold-air, four-step Otto cycle, and added temperature dependent properties, a phenomenological combustion model, heat of combustion, variable valve opening and closing profiles, compressible flow blow-down, exhaust and intake strokes, cylinder wall heat transfer, and variable intake conditions.
This figure outlines the project topics and concurrent lecture topics throughout the semester.
 Not every lecture topic was used in the engine model, but most topics were used directly or were closely related to project material.
This figure shows an air standard Otto cycle plotted in P-V coordinates which was the result of the first assignment.


The next two figures show an intermediate plot from about half-way through the semester, and a plot from the last assignment of the project.

While this approach did provide the desired framework for structuring the class, and was enjoyable for most students, it also had some drawbacks.  First, not everybody has an interest in internal combustion engines (imagine that!), so having the entire class structured around that subject didn’t please everyone.  Also, it involved a lot of computer programming which was easy for some students but provided an additional challenge, separate from learning the thermodynamic principles, for others.


Stevens, James W., “A Project-structured Approach to a Graduate-level Advanced Thermodynamics Class,” Proceedings of the 2013 American Society for Engineering Education Rocky Mountain Section Conference, pp. 27-36.
available here:
http://www.asee.org/papers-and-publications/papers/section-proceedings/rocky-mountain/2013.pdf


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