Alan Shih, Ph.D., professor of mechanical engineering, has spent most of his career working on simulations. His research interests range from computational geometry to virtual reality, among others.
But Shih has wanted to research wind turbines since he arrived at UAB in 2002 - years before the current alternative energy boom. His problem was a lack of time and of help.
Then Shih met student Kevin Nord three years ago, and the possibilities of beginning his wind-turbine research began to take shape.
"Kevin was a mechanical engineering student in the Science & Technology Honors Program and performed very well in my programming class," Shih says. "I recruited him after the class to work in my lab as a research assistant and had him test the geometry-generation software that we developed here."
Nord soon began working on the turbine-blade design using the software and performed numerous simulations. The project reached a peak this past week when a turbine designed, developed and produced by Shih's mechanical and materials engineering students was mounted atop the 18-story Alabama Power headquarters building at 600 North 18th Street in Birmingham. The group, led by Nord, came together to complete the turbine for its senior design project.
The wind turbine was mounted on a pole April 28 and raised approximately 19 feet above the roof; it will collect wind and power data that Shih and Southern Company Principal Engineer Liz Philpot will be able to analyze. Southern Company is Alabama Power's parent company.
"Southern Company is researching how to measure and produce energy from the wind given the fact that Alabama really is a low-wind area," Shih says. "Still, it's an alternate energy, and it's an area we all believe is worth researching and investigating."
Philpot, who closely follows technology developments that may aid Southern Company, says the fact a low-wind area location doesn't mean the technology can't - and shouldn't - be pursued.
"I focus on renewable energies - wind, solar and hydro - and try to find technologies that will work in our footprint," Philpot says. "There are other parts of the country where this might be more applicable, but this is not stopping my research. One day there may be a turbine that will be able to capture the wind here and harness it, and maybe it will be Dr. Shih and his students who will develop a blade that will capture more wind. There are a lot of positives here for us in working with UAB on this project."
Designing the turbine
Nord already had worked on the project for three years before bringing it to the five-person senior design team he was leading this semester.
Nord began the project as a sophomore by using geometry-generation code to create a template for wind-turbine blades. Shih wanted to see how well the geometry code could be applied to certain applications and if it could be used to parametrically define the shape of a blade. Once Nord mastered that, Shih had him use the blade he generated and analyze it computationally.
Nord then began using the computational fluid-dynamics code developed by Roy Koomullil, Ph.D., associate professor of mechanical engineering, to simulate numerically how well a blade can perform. Those findings led him to refine the geometry of the blade, and in the process he developed a simulation loop using various tools to refine the blades and simulate their performance.
"Kevin had to refine the geometry and simulate the performances several times, and he went through iterations of different designs by varying the parameters," Shih says. "By changing the parameters, you can come up with a different blade design. From the simulation of these blade designs, you will then be able to figure out which one performs better - at least in theory."
Nord chose the best-performing blade design and assembled a group of other students for the senior design project. Now that they had the geometry and definition of the blade, they needed to actually make one.
Collin Metzger, a student in materials engineering, was part of Nord's team and had to discern which materials were best to build the turbine and blades.
Choosing the steel pole and aluminum hub for the base was the easy part, he says, but deciding what to use to build the blades was tricky. Metzger initially chose foam, but balsa wood could be cut and shaped better by the School of Engineering CNC machines. He then took glass fiber that has the consistency of cloth and wrapped it around the balsa wood blade before using a resin to saturate the glass fiber. When it cured, they had their fiberglass-reinforced blades with balsa wood core.
"I had never done this before, so it was interesting to see it come to life," Metzger says. "The other team members, I don't want to say they had doubts, but they were curious how it would work considering how weak the balsa wood is. But when you put the fiberglass on it, it's really a 'wow' moment when you see how strong it is."
With help from teammates and mechanical engineering students Danielle Caren and Christopher Yancey, the group manufactured a set of three blades. It took more than five hours to mill the balsa core and another day to reinforce it with fiberglass and resin for each blade.
The blades are 20 inches in length and hub is seven inches in diameter. The wind turbine measures close to a 46-inch swept diameter.
Nord says seeing the project from its beginning to this point has been an important learning experience for him.
"I have had the opportunity to learn all of the different aspects of the project, from the project concept to the computational testing to the actual construction," Nord says. "Having been a part of all of the steps along the way has been really beneficial and helped in my decision-making and design approach. And to have the assistance and help of Southern Company is invaluable."
"This is our first attempt in wind-turbine design, and there certainly are many things that we have to learn from failures," Shih adds. "But with this energetic team of engineering students, we made our first baby step."
Future work will continue
Alabama Power had to get FAA approval to put the turbine on its roof because the building is in the flight path to the Birmingham-Shuttlesworth International Airport. The company also had to get approval from the City of Birmingham Design and Review Committee and hire civil and electrical engineers to design and construct the ideal way to connect the turbine to the roof and collect wind data.
The mount was designed so Shih's future senior design students can continue to refine and research wind turbines, says Steve Swartz, building facilities manager at Alabama Power.
"This is not a one-shot deal," Swartz says. "We'll be able to raise and lower the turbine as needed. It's set up so we'll be able to continue to work with UAB engineering students and enable them to improve and work on this design for the foreseeable future."
Shih already has another undergraduate student working on a different turbine design. He plans to continue to refine the wind-turbine blades.
"I hope the site can become a test site for new blades or bigger blades, for example," Shih says. "It's certainly an ideal site to have - a very good, windy site. The timing worked out very well for all of us. We can't thank Southern Company enough for their generosity and help with this project."