More than a quarter of a million — specifically, 280,000. That’s how many people there are worldwide who need to replace their native heart valve with a new artificial one every year.

Then, that valve needs to be replaced after every 15 years. With a demand like this, a group of research students led by Ming-Chen Hsu, assistant professor of mechanical engineering, is striving to make improvements in how industry models different products. For Hsu and his team, these improvements are on heart valves and wind turbines.

While heart valves and wind turbines don’t seem to have a link, Hsu said they are similar in Computational Fluid-Structure Interaction.

“A lot of physics you are looking at involves the interactions between fluids and solids,” Hsu said. “In this case, the blood flow drives the vibration of the leaflet. The leaflet opens and closes. That [structural] motion also interacts with the fluid. Once that leaflet closes, the flow stops.”

The process to model an artificial heart valve, as well as other mechanisms, has become markedly faster in the past two decades.

“Fifteen years ago … people in mechanical engineering, when they want to test something, they build it and then they test it to see the performance of the design,” Hsu said. “With computational engineering, instead of building the models literally, you model them in the computers and use a mathematical formula.”

With the software Hsu and his research team of five graduate students and two undergraduate students use, they can see how fluid moves around a model. For example, when a heart valve’s leaflets move, they can see the fluid interaction with the structure of the heart valve. This can be applied with wind turbine blades with how air moves around the blade and how it affects the blades.

“We don’t know for certain that we have the best, most efficient wind turbine blade design,” said Austin Herrema, graduate student in mechanical engineering and the wind energy science engineering and policy graduate program. “There are so many things you can change. [With our research], I’d like to see at least a small contribution toward more efficient wind turbine technology, making more electricity using less money.”

The code Hsu and his team use to write data files was even written by them. They then use other software to read the files their code writes, where they physically see how the fluids and structures of the heart valves and wind turbines move together.

Hsu hopes the research can aid future scientists in building wind turbine blades that are more efficient by testing them with realistic computer models. This saves time and money.

Hsu hopes that with his contributions to the research of heart valves, more time can be added to the lifespan of an artificial heart valve.

Fei Xu, graduate student in mechanical engineering, said heart valves are the perfect topic to test computational mechanics on.

“Recently, it’s become a hot topic,” Xu said. “Every 10 to 15 years, [people with artificial heart valves] need surgery to replace it. We want to better understand why the artificial heart valve gets fatigued. After we understand that, we can improve the durability.”

All of this work isn’t just about finding results. It’s also helping students learn how to work in teams and improve their experiences in the classroom. Carolyn Darling, senior in mechanical engineering, said Hsu was one of her professors and because of him, she decided to look into researching wind turbines. She discovered her love of coding through that research.

“I was introduced to new programs and coding languages,” Darling said. “I am doing a lot of MatLab in my classes now, and because I’ve had experience with it previously, it has helped me a lot. I plan on taking classes in the future where they use the design software that I’ve been using.” 

With their research, Hsu and his team hope to see improvements with wind turbines and heart valves over time. 

The team and Hsu are proud to contribute to something that could save a person’s life or could produce more renewable energy for the world.