An ambitious project in propulsion was introduced as part of the final-year integrator project offerings of the mechanical and aerospace engineering programs at École Polytechnique de Montréal in 2011–2012. It has been running successfully for the past three academic years. The project consists in the design, fabrication, and placement into service of a functional instrumented multistage compressor test rig, including the compressor, for research in compressor aerodynamics. A team of 15–17 senior-year undergraduate engineering students is given a set of design and performance specifications and measurement requirements, an electric motor and drive, a data acquisition system, and some measurement probes. They must complete the project in two semesters with a budget on the order of Can$15,000. The compressor is made from rapid prototyping to keep production cost and time reasonable. However, the required rotation speed of 7200 rpm stretches the limits of the plastic material and presents the same structural challenges as industrial compressors running at higher speeds. The students are split into subteams according to the required disciplines, namely, compressor aerodynamics, general aerodynamics, structures, dynamics, mechanical design and integration, instrumentation, and project management. For the initial phase, which covers the first two months, the students receive short seminars from experts in academia and industry in each discipline and use the knowledge from fundamental engineering courses to analytically model the different components to come up with a preliminary design. In the second phase, covering three to six, the students are trained at commercial simulation tools and use them for detailed analysis to refine and finalize the design. In each of the first two phases, the students present their work in design reviews with a jury made up of engineers from industry and supervising professors. During the final phase, the compressor is built and tested with data acquisition and motor control programs written by the students. Finally, the students present their results with comparison of measured performance with numerical and analytical predictions from the first two phases and hand over their compressor rig with design and test reports as well as a user manual and an assembly/maintenance manual. This complete project allows the students to put into practice virtually all the courses of their undergraduate engineering curriculum while giving them an extensive taste of the rich and intellectually challenging environment of gas turbine and turbomachinery engineering.
Using a Project-Based Learning Approach to Teach Mechanical Design to First-Year Engineering Students
