Making Waves
Angela Pelletier loves water. It all started when her mom dunked baby Angela during an infant swim class—never suspecting she might be launching her daughter’s career path. But two decades later, the UNH senior is en route to Johns Hopkins for a Ph.D. in mechanical engineering. She’ll be specializing in fluid mechanics.
Pelletier’s growing up years were filled with water sports, summers at the lake, trips to the beach. Her love of the water even defined her college choice. “I wanted to design ships,” she says. “I figured a minor in ocean engineering would be a good springboard into naval architecture.”
As it turns out, the mechanical engineering major has a minor in applied math, as well as a concentration in ocean engineering. Along the way, she’s been making waves, literally. And she’s done it so successfully, she went to Capitol Hill to present her research.
Pelletier’s journey to Washington, D.C., began last year, when she won a grant from IROP. She spent the summer at Scotland’s Heriot-Watt University, testing a scale model of a wave-rider buoy in a multi-dimensional wave tank, ideal for simulating stormy seas. (The tank in UNH’s Ocean Engineering Building is long and narrow, ideal for creating currents, but not the choppy waters Pelletier’s work requires.)??Working from a room next to the swimming-pool sized tank, Pelletier hit a computer key to start the paddles that created the waves. Then she dashed across the room to another computer and punched another key, triggering the infrared camera that recorded the motion of the buoy. And then she stood by the edge of the tank and watched. The waves churned, the buoy pitched and rolled. For 17 minutes, the waters raged—a perfect storm created in her own little ocean. Then she went back and checked her data.
“What I was looking for was the response amplitude operator (RAO),” she says rattling off an explanation of how to measure the heave motion, or vertical displacement, of a buoy. The goal, in short, is to determine how big the wave is. Her layman’s version of the process? “Basically, you throw some waves at something, measure the waves, measure the motion of the object, and use the computer to get the data you need.”
The Scotland buoy is a model of an actual wave-rider buoy near the Isle of Shoals, just off the New Hampshire coast. Data from this buoy helps determine how the cages and feed buoy at this location will behave under various conditions. The model buoy experiments are critical in determining whether the actual buoy is working correctly—whether it is providing accurate wave motion measurements.
Pelletier’s research could play a significant role in the future of open ocean aquaculture in New England. Understanding wave motion is important for all sorts of reasons: Fishermen need to know how their boats will fare. Meteorologists are interested because wave height helps predict weather patterns. Biologists know that rougher sea states affect what creatures can survive.
Back at UNH, Pelletier put her expertise to immediate use during her senior project, which involved more buoy research. “Every single thing I learned during IROP, I taught to my group,” she says. Then she shared her knowledge with another group, members of the U.S. Congress. And now it’s on to the next challenge, graduate school—and she’s clearly eager to plunge right in. Just what you’d expect from a water enthusiast.
--Suki Casanave, UNH Magazine
