Flow control for turbulence and complex fluids

This seminar will start by introducing diverse fluid-mechanics projects conducted in the Park Research Group at Nebraska. I will then focus on two projects at very different Reynolds number regimes. For both projects, the modeling, analysis, and computation will be presented along with their engineering applications. The first part is dedicated to a high Reynolds number flow (turbulent flow), where three flow-control methods, namely adding polymers, utilizing slippery surfaces, and applying external forces, are investigated for skin-friction drag reduction. I will present their underlying mechanisms of turbulent drag reduction. The second part is dedicated to a low Reynolds number flow (Stokes flow), where dynamics and rheology of conductive microparticle suspensions in an electric field are investigated. In particular, I will present rheology control for shear thinning, shear thickening, and gel formation of such complex fluids via the magnitude and frequency of the electric field.

Dr. Jae Sung Park is Richard L. McNeel Associate Professor of Engineering in the Department of Mechanical and Materials Engineering at the University of Nebraska-Lincoln (UNL). He received his B.S. from Hanyang University in 2006 and his M.S. and Ph.D. from the University of Illinois at Urbana-Champaign in 2008 and 2012, respectively. All degrees are in Mechanical Engineering. Prior to coming to UNL in 2017, Dr. Park was a postdoctoral researcher in the Department of Chemical and Biological Engineering at the University of Wisconsin-Madison from 2012 to 2016. His research encompasses a wide range of fluid mechanics from small to large scales, involving complex fluids, rheology, transition-to-turbulence, and turbulence. He has been awarded the UNL College of Engineering New Faculty Teaching Award in 2020, NSF CAREER Award in 2021, UNL College of Engineering Research Excellence Award in 2023, UNL University-wide Teaching Award in 2024, ASME Rising Stars of Mechanical Engineering in 2024, and Best Presentation Award at KSME Annual Meeting–International Session in 2024.