Alec Petersen Receives 2016 NSF Graduate Research Fellowship

Alec Petersen, a graduate student in the AEM Department, has been named as a recipient of a NSF Graduate Research Fellowship. The NSF selects individuals for the prestigious Graduate Research Fellowship Program (GRFP) based on their proven potential to make significant contributions to science and engineering. Historically, the recipients of the GRFP have gone on to become pioneers and life-long leaders in their fields. The GRFP received close to 17,000 applications for the 2016 competition and of those applicants, 2,000 were chosen to receive the Fellowship. The GRFP provides an annual monetary award for three years in order to support the graduate student as he or she pursues a research-based master's or doctoral degree in science or engineering.

In response to receiving the NSF Fellowship, Petersen says, "I'm very grateful for my adviser, Filippo, and all the others I work with here at the University who have helped me evolve as a scientist. I'm also beyond thankful for those in the Behringer Lab at Duke who first got me involved in research and without whom I would have never been considered for this fellowship."

Petersen received his undergraduate degree from Duke University where he studied physics. While at Duke, he had the opportunity to conduct research on granular physics in Professor Robert Behringer's lab. Currently, Petersen is studying multiphase turbulent fluid dynamics--in other words, how small solid particles move around, organize themselves in a turbulent air flow, and their collective effect on the turbulence itself, with Professor Filippo Coletti and graduate student, Doug Carter. For the project, Petersen, Coletti, and Carter created a "giant turbulence box" at the Saint Anthony Falls Laboratory (SAFL), "consisting of 256 air jets that blast at each other, generating homogeneous turbulence in the center of the four cubic meter test-section." In describing the project, Petersen explains, "We use particle image velocimetry (PIV) to investigate the dynamics of our turbulent flow. As designed, we can produce intense turbulence with a negligible mean flow over a large volume. This is crucial for investigating particle dynamics in turbulence, analogous to that found in the atmosphere--which is the motivation for much of this work. Inertial particles are too heavy to perfectly follow turbulent fluctuations, leading to a variety of unexpected behaviors--how the particles cluster, collide, and the speed at which they fall are all drastically affected by their coupling with the fluid flow. Those behaviors could play a role in a wide range of atmospheric phenomena like rain droplet formation in clouds, or transport and deposition of volcanic ash."

Regarding the AEM Department at the U of M, Petersen says he appreciates, "the breadth of research going on. I'm doing fundamental experimental fluid dynamics research--and I'm more interested in environmental fluid flows than industrial ones, so I'm glad I have the freedom to explore topics not necessarily related to designing airplanes." Petersen also enjoys the collaboration between the AEM, Mechanical, and Civil Engineering Departments, as well as SAFL. He says, "It has expanded the community of fluid dynamicists I'm exposed to."

In the future, Petersen can see himself working for NASA, studying the fluid mechanics of volcanoes, or, he admits, "maybe something totally unrelated to everything I've done with my life so far". Wherever his academic and professional career may lead, the AEM Department is looking forward to Petersen's future successes and congratulates him on his terrific work thus far.