Vortex Dynamics in the Exotic Wakes of Bluff Bodies

Wednesday, March 14, 2018

2:30-3:45pm


330 Lavery Hall

Dr. Mark Stremler
Biomedical Engineering and Mechanics
Virginia Tech

ABSTRACT:

Bluff body wakes with clearly defined vortex structures are found in a wide variety of flow systems over a broad range of Reynolds number.  The structure and dynamics of a vortex wake can have a significant effect on the object forming the wake and on other objects that enter the wake flow.  Application areas range from atmospheric flows to insect flight and include both established engineering systems, such as bridges and oil risers, and emerging systems, such as biomimetic micro-air vehicles.  The classic wake pattern known as the von Karman vortex street occurs commonly behind fixed, isolated objects.  The information provided by von Karman's simple, 117-year-old model still proves useful today.  However, if the wake-producing body is moving, or if multiple wake-producing bodies are in close proximity, the resulting vortex wake pattern can be quite different from the classical vortex street. We will discuss experimental and modeling results that explore the dynamics of these ‘exotic' wakes, which exhibit a rich variety of relative vortex motions.  Despite the complexity of this system, reduced-order mathematical modeling provides key insights into the wake dynamics.  

BIOGRAPHY:

Mark Stremler is a professor in the Department of Biomedical Engineering and Mechanics at Virginia Tech.  His research interests include the study of laminar flows, particularly mixing and separation in highly viscous fluids and/or small scale systems, and fluid transport and mixing in biological systems; the dynamics of flows dominated by coherent vortical structures; and chaos and dynamical systems theory, including topological chaos and applications to fluid motion.  He received his PhD in theoretical and applied mechanics from the University of Illinois at Urbana-Champaign (UIUC).  Prior to joining Virginia Tech in 2006, he was an assistant professor of mechanical engineering at Vanderbilt University and a postdoctoral research associate in the Beckman Institute for Advanced Science and Technology at UIUC.