Dean of the College of Engineering and Applied Sciences, Fotis Sotiropoulos, has spent the last 10 years on a mission to expand the use of hydropower in the United States.

Sotiropoulos’ goal is to serve up to 10 percent of the nation’s energy needs in a renewable and sustainable manner, using tidal power from rivers. Most of his work has been in the field of fluid dynamics, the study of how liquids and gases move and interact with static objects.

“I have been looking for problems,” Sotiropoulos said of his research. “Problems that are important for society, and how this type of research can help solve those problems.”

Results from the professor’s theoretical work have been put to use in Verdant Power’s Roosevelt Island Tidal Energy (RITE) pilot project, at the East River in New York City. The project will deliver power to 9,500 NYC residents.

Sandy rivers have long posed a predicament for those who wish to harvest energy using hydropower, which is electricity generated by the motion of a body of water. Scientists feared that shifting sand dunes on the riverbed could cover the turbines used to collect the energy. They also believed that the presence of the turbines could compromise the stability of the riverbed.

Sotiropoulos disproved these fears with his paper, published in Nature Energy this July. The paper demonstrates that the turbines modify the flow to prevent any sand accumulation. His experimental work at the Saint Anthony Falls Laboratory in Minnesota also showed the turbines do not impact the structural integrity of the riverbed.

A large factor that prevents sandy rivers from being used to harvest energy is the underdevelopment of viable computational models that could help design the most optimal configurations of turbines.

Optimizing the configuration of the turbines is the subject of the professor’s current work at Stony Brook. Sotiropoulos and his team have already developed a model that works for sedimentary rivers with one turbine, and are in the process of making one that works with multiple turbines.

Sotiropoulos’ research involves making models that include multiple turbines in a sandy river, at which point a pilot model can be planted in some sandy rivers. Sotiropoulos also said that the Long Island Sound is a particularly fertile energy source that he is looking at.

“It is important to do research that has an applied focus to solve a problem, and to do it well one needs to do fundamental research,” he said.