Nature-based engineering

Drawing inspiration from nature, PSU researchers aim to improve the form and function of cylindrical structures.

Seal swimming in water
PSU researchers turn to seal whiskers for engineering inspiration.

Can seal whiskers help us design better wind and solar farms, suspension bridges, and more?

With support from the National Science Foundation (NSF), Portland State mechanical and materials engineering professor Raúl Bayoán Cal, along with collaborators from the University of Wisconsin-Madison, and the Naval Undersea Warfare Center, aims to find out.

Cal is a member of the Thermal & Fluid Science Group at PSU, where his research focuses on turbulence resulting from fluid dynamics. His group examines applied and fundamental engineering problems, looking at natural and engineering systems as they interact with the atmosphere including volcanic eruptions, wind and solar energy as well as the interactions between airflow and surfaces through theoretical and experimental approaches.

Cal and his colleagues recently received a three-year, $460k grant from the NSF to investigate how applying the unique geometries of seal whiskers to cylindrical structures could reduce undesired vibrational forces and how these structural variations could impact systems of closely packed structures.

According to Cal, seal whiskers, unlike those of many other animals, have undulated surfaces that help them detect wakes and changes in flow caused by prey. Research has shown that the undulated surface structures also significantly reduces forces and vibrations that result from interactions with fluids.

Using a combination of wind tunnel experiments and computational simulations, Cal and the research team will study the interactions between fluid flow and undulated cylindrical structures. The results of the research could aid improved design and engineering practices by providing insights into undesired vibrational forces on cylindrical structures. 

"We're looking to nature to improve systems of cylindrical structures," Cal said. "We want to understand how the interactions between undulated cylinders individually and in groups impact flow patterns and provide us with information we can use to address unwanted vibrations and improve flow through large arrays of these structures."

The research has applications in a variety of fields, Cal noted. Undulated cylinders could reduce the cost of wind turbines and increase the amount of electricity they can generate. On solar farms, undulated cylinder technologies could provide additional protection from harsh weather conditions. The research also could improve our understanding of how weather systems interact with forests, among other practical applications.

"We live in a turbulent environment," Cal said. "The better we understand how to mitigate the effects of turbulence where the better off we all are."

The research team will begin their work in January 2021. The project will support two Ph.D. students, one in Cal's lab and one in professor Jennifer Franck's lab at the University of Wisconsin-Madison. Additionally, the project will provide research opportunities for undergraduate students interested in studying fluid dynamics.