When you need a trailer for research purposes, you can’t get any luckier than Purdue University engineering researchers. The largest trailer manufacturer in the United States just happened to be a 15-minute drive away.
The engineers took advantage of the opportunity and have teamed up with Wabash to investigate an experimental trailer that recaptures its own electricity from vibrations, heat and airflow.
The donated trailer is part of a three-year collaborative research project between Wabash, which is headquartered in Lafayette, Indiana, and Purdue University’s College of Engineering.
The trailer was recently showcased at an open house at Purdue’s Herrick Labs, where the first experiments are taking place.
Michael Bodey, the Director of Technology Discovery and Validation at Wabash, said the goal is to find cost-efficient sustainability solutions that also take advantage of the available waste energy from both vehicle movement and payload. That usable energy, he said, could be used for things like propulsion, lights and electric TRU systems.
“When you think of a trailer in transport, the weight and speed of the system itself have a lot of potential energy available from the sheer motion of the trailer,” Bodey explained. “Now, if you add in all the different factors that would affect how much energy could be collected – the wind going around it, the amount that it takes to start and stop, the natural vibrations of movement – it is all being wasted. That led us to propose the question; what if we could turn that energy into something usable? What would it look like?”
Leading the project as one of its principal investigators is Associate Professor of Mechanical Engineering, James Gibert.
“Wabash has been a dream to work with,” he said “They’re actively engaged, they’re supportive, they’re flexible, and they’re immediate in giving their feedback,” he said. “The best possible outcome for any engineer is having an impact on the world, and Wabash certainly shares that vision.”
Gibert’s field of expertise is smart materials, especially in the realms of dynamics and vibration. His previous work has included embedding triboelectric generators into cardboard packaging, whose natural movement during the delivery process generates enough electricity to power sensors embedded in the boxes. Scaling up that process to something the size of a semi-trailer was the next logical step.
In broad terms, the collaboration is investigating ways to harvest electricity from a trailer’s normal operation. Those modalities could be the vibration of the suspension system, aeroelastic vibrations of the composite panels or harvesting the air used in the braking system.
“The scale is much bigger than anything we’ve worked with before,” said Gibert. “But that’s a good thing. A semi-trailer has lots of mass, which means lots of opportunities for that mass to be utilised in ways it hasn’t before. Plus, there’s an increasing regulatory push for these vehicles to be more energy efficient.”
Currently in phase one of the project, the team is focused on understanding what exists on the trailer and in research. Tasks involve, retrofitting the trailer with displacement sensors, accelerometers, anemometers, pressure gauges and many other measurement tools.
After Gibert and his team at Herrick Labs have turned the trailer into a mobile data acquisition system, Wabash personnel will take the truck onto the highways of Indiana for some short-haul and long-haul test drives. Once the Purdue team have collected data from the test drives, they will coalesce around the energy-harvesting methods that are most promising.
Through Purdue’s research, the Wabash team has been able to look at how other industries are tackling very similar problems and exploring how to apply that to a trailer.
“We plan to conduct trials with a fully instrumented trailer first,” Bodey said. “Then as we progress, we will collect data with the trailer on roads representing different regions of the country. For example, driving on flat roads compared to mountainous terrain has very different road conditions and implications.”
In terms of outcomes, Gibert said that reducing a trailer’s electrical load, even by a little bit, is a success.
“By diversifying the load, we can reduce the size of the batteries required,” he said. “Lighter batteries mean less weight, which leads to even more efficient operation. So, it becomes a positive feedback loop.”
For Wabash, being involved from the beginning has had a number of advantages, and the two sides – commercial and research – meet regularly to review and talk through their learnings.
Bodey said the best part, however, is taking the research and putting it into real terms.
“This isn’t a research project that’s only going to produce PowerPoint slides,” he said. “We’re developing a full 53-foot instrumented energy harvesting trailer to explore the potential of energy utilisation for electrification, with the end goal of investigating how such technology can contribute to the decarbonisation of the industry.”
In the final phase, Purdue and Wabash plan to collaborate on a deliverable product that can be scaled up and deployed to trailers around the world.
