Sven Schmitz wants to know why wind turbines rarely operate as efficiently or as durably as expected. In fact, so much remains unknown about wind power generation that the Penn State assistant professor of aerospace engineering likens the state of the technology today to the state of aeronautics shortly after the Wright Brothers’ flight at Kitty Hawk. Their airplane did fly, just as today’s wind turbines do spin and create electricity. However, it took Wilbur and Orville and others many years to figure out the theory behind flight, and it may take engineers like Schmitz many years to understand and optimize wind power generation as well.
“Right now, we are all wondering what in heaven’s name is going on with the blades,” said Schmitz. “Beyond maximizing efficient power generation, the difficulty is protecting the turbine from premature fatigue. Wind speed is one factor, but even more important and more confounding are unsteady aerodynamic loads caused by atmospheric turbulence.”
Then Schmitz, who can’t help himself, adds, “At the moment, we do not understand a wide range of physical phenomena in wind power generation. But the answer is out there.” He grins. “It’s blowing in the wind.”
For many aerospace engineers, job security derives from exactly the complexity Schmitz is describing, the complexity associated with fluid flow around a body in motion, also known as fluid dynamics. For that reason, the engineer studies and attempts to computationally model interactional aerodynamics on helicopter rotors, wind turbine blades, and wings. “What we do in computational fluid dynamics is solve numerically a problem that has been described in terms of a mathematical model, then critically evaluate all the results we obtained,” said Schmitz. “Obviously, this isn’t something that my pocket calculator or my desktop computer can do. It takes high-level processing power.”
Schmitz’s research interests further include developing best practices to help wind turbine operators adjust blade angle, pitch and speed so that the machines can ride out an ice storm and its aftermath with minimal damage and power degradation, and assessing the complex flows around helicopter rotor hubs using one-quarter scale models submerged in the Garfield Thomas Water Tunnel at ARL (the Applied Research Lab) Penn State. As an educator, Schmitz is helping to build a 9-credit graduate certificate in wind energy that can be offered via distance education, and supporting an initiative to improve the teaching of engineering by using graduate students to advise undergraduate research projects.
Schmitz grew up in Effeld, Germany, a village of 1,000 people near the Dutch border where his parents were also born. “We are an unusual and independent crowd among castles and forests,” said Schmitz. “Over the centuries, we have strived repeatedly for political independence.”
Effeld’s powerful community spirit also manifests itself in a soccer club and a 75-man marching band; Schmitz participated in both. In fact, Schmitz’s grandfather was one of the band’s founding members, and Schmitz and his father played flute together in its signature blue-and-white uniforms for more than 20 years.
Indirectly it was the band that inspired Schmitz’s move to the United States. In 1998, he was a senior engineering student at RWTH (Rheinisch-Westfaelische Technische Hochschule) Aachen University when the band was chosen to march in the annual Steuben Parade in New York City. The parade was a lot of fun as was the party afterward in Central Park where Schmitz made friends with everyone from West Point cadets to New York City police officers. When the following year, Schmitz had the opportunity to study in the United States -- at the University of California, Davis -- he jumped at the chance.
At Davis, he encountered two major diversions. The first was a helicoidal vortex model for predicting wind turbine performance, his adviser’s approach to understanding some of the more vexing fluid dynamics issues posed by wind power generation. Up till then, Schmitz’s academic focus had been thermodynamics and rocketry. But Mechanical- and Aeronautical Engineering Professor Jean-Jacques Chattot’s model was so clever it not only led to several successful research projects and publications, it shifted Schmitz’s attention to wind energy.
The second diversion? An Italian graduate student studying the viruses that sicken grape vines.
After the year at Davis, Schmitz took a hiatus both from wind power and romance to accept a prestigious appointment at EADS (the European Aeronautic Defense and Space agency) Astrium Space in Munich, where he researched his master’s thesis, “Numerical Simulation of the Flow in Cooling Channels of Rocket Combustion Chambers using Coupled Simulation VADUCT.”
To complete his Ph.D., Schmitz could have stayed in Munich but chose Davis due to his two diversions. Schmitz notes that when he first left Europe to study in the United States, his mother predicted he would find someone to marry and never come back, and in the end that was exactly what happened. He married in 2004, earned his Ph.D. and worked on postdoctoral projects including rotorcraft aeromechanics problems for the U.S. Army Aeroflightdynamics Directorate, and wind turbine aerodynamics for General Electric. Meanwhile, his new wife finished her own studies at Davis.
Recalling his past, Schmitz sees a succession of lucky breaks. He was a math and science kind of kid – he even took a calculator to kindergarten – but chose engineering at university primarily because he fit in better with engineers than with physicists. He elected to return to Davis, and a few months later budget cuts at EADS eliminated what would have been his funding. Then there is the matter of his coming to Penn State in the fall of 2010.
“When I got here to State College to interview, everything was blue and white like the marching band colors in Effeld,” he remembers, “and the trees smelled like home.”
Schmitz called his wife back in California, and told her to pack up their son and come to State College to take a look. Today, his wife works as a research associate in the College of Agriculture, their son attends a Penn State preschool, and the family lives on a tree-lined street within walking distance of the University Park campus.
Aerodynamics, wind energy and rotorcraft aeromechanics. His research interests further include developing best practices to help wind turbine operators adjust blade angle, pitch and speed so that the machines can ride out an ice storm and its aftermath with minimal damage and power degradation, and assessing the complex flows around helicopter rotor hubs using one-quarter scale models submerged in the Garfield Thomas Water Tunnel at ARL (the Applied Research Lab).