By Dr. Ewan Pritchard
During the last week of NC State University’s fall semester, all engineering students competed for coveted first place finishes in their senior design courses. I was lucky enough to serve as the champion for a whole course of mechanical engineers who competed to build contributing materials for the NCSU EcoCAR 2 team. While I had attended a number of critical design reviews earlier in the semester, I was completely unprepared for what I was about to witness. Six teams presented about project management, engineering design, prototype build and final optimization to meet a number of key competition criteria.
Four of the teams competed head to head to design a mechanism that would quickly and easily remove the 400 pound battery pack from the vehicle. Because the vehicle’s battery pack is located in the bottom of the trunk area, sponsors identified removal and troubleshooting as a concern. I recall sponsors citing that it would be unheard-of to remove or install the battery pack in under 30 minutes.
The engineering teams proved that assessment wrong: Each of the teams demonstrated technologies that could remove and install a 500 pound battery mock up in under seven minutes! Ultimately, the winning team of the battery designs developed a passive solution that uses quick install tracks and wheels which allow the pack to roll smoothly out of the vehicle along a prescribed path using an engine hoist. Another winning design uses dual winches to simulate a combination forklift and bucket truck mechanism that can also be fitted onto an engine hoist.
The remaining two teams chose projects that help the team with the engine and motor side of the vehicle. One team designed and tested a diesel exhaust and muffler system using dual Helmholtz resonators to eliminate excess noise. As an added bonus, this team was able to commission the department’s engine dynamometer facility which is necessary to characterize and optimize the small diesel engine for the vehicle. The final team was the overall winner of the event. This team developed and designed mounting brackets and noise, vibration and harshness (NVH) isolation for the engine, generator and drive motor for the vehicle. With this critical design, the team now has all major components mounted within the vehicle in a clear and clean way. This provided much needed breathing room for the volunteer EcoCAR 2 team to focus on system integration and controls development.
It was amazing to see just how these teams were able to contribute so much to the overall program by focusing on specific problems within the vehicle. It was a tremendous lesson in leadership, planning and orchestration which will serve as an example to the rest of the team about the value of teamwork. I am confident these lessons will make NCSU Engineers much stronger in their future careers.