Modeling Fluid Dynamics Originally, Christel Hohenegger, assistant professor of mathematics, had wanted to study chemistry because she thought that reaction equations were beautiful. But she didn’t like doing the lab work and decided instead to study mathematics, without a clear idea of what a mathematician does—she just knew that she liked structure and order. Later, as an undergraduate at the renowned Eidgenössische Technische Hochschule Zürich (ETH Zurich), she took a course in the history of math and learned about all of the famous mathematicians who taught at the ETH. “I found it fascinating to learn that they were trying to answer both math and physics questions,” said Hohenegger. After graduating from the ETH, she earned a Ph.D. from the Georgia Institute of Technology.
Practical Applications Hohenegger’s research focuses on questions concerning fluid dynamics that can be solved using different mathematical tools from modeling and analysis to simulations and predictions. “I study how solid objects and liquids interact in a fashion that is counterintuitive,” said Hohenegger. “For example, I look at models of swimming organisms in water, where reciprocal swimming results in zero net displacement. Or I’m interested in how the stickiness and gooeyness of a liquid can affect how far an object moves.” Brownian motion is used to describe the random motion of particles suspended in a fluid resulting from their collision with other fast-moving molecules in the fluid. In a complex fluid with memory, such as ketchup or mucus, the particle motion is different. Hohenegger, along with colleague Scott McKinley, associate professor of mathematics at Tulane University, developed a framework to model these kinds of interactions. Her research has practical applications in many industries, such as pharmaceuticals and aerospace. “Understanding how particles diffuse in a complex fluid or knowing how much time it takes a sphere to traverse a layer has potential application in drug delivery,” she explained. “In aerospace, understanding how and at which frequency a liquid will slosh around the wall of a container is a problem associated with aerospace engineering, particularly in designing rocket boosters.”
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