High-resolution velocimetry for turbulent flows
Ohio State University
Abstract
Turbulent flows are ubiquitous in nature and engineering systems, thus necessitating an understanding of the basic physics governing their behavior. In experimental fluid dynamics research, quantitative velocity measurements are paramount for describing flows, their impact on nearby bodies, and the generation of aero/hydrodynamic forces that underpin power generation, ground transportation, and aerospace systems. For turbulent flows, experimental requirements are stringent due to their highly three-dimensional nature and broad range of length and time scales. For the last three decades, optical and laser-based measurement approaches have emerged as the primary investigative tools with particle image velocimetry (PIV) becoming the de facto method for determining fluid velocities. Traditional PIV (based on cross correlation processing) is well established but suffers from spatial resolution limitations which can lead to inaccuracies in high-gradient regions of turbulent flows and in calculating critical derivative quantities. Optical flow motion estimation (OFME) presents an alternative to traditional cross-correlation-based PIV and produces velocity fields that are dense (one vector per pixel) and more accurate. In this talk, I will discuss the development and application of one particular OFME approach, termed wavelet-based optical flow velocimetry (wOFV). wOFV provides the opportunity to increase measurement spatial resolution by more than a decade with significant increases in accuracy. Specific case studies using synthetic and experimental data will be presented that quantify the gains in resolution and accuracy using wOFV compared to traditional PIV. I will discuss recent extensions of planar, two-component wOFV to stereoscopic and tomographic implementations and finally discuss future directions and implementations into challenging environments such as hypersonic boundary layers.
About the speaker
Prof. Jeffrey A. Sutton is a Professor within the Department of Mechanical and Aerospace Engineering at Ohio State University and the director of the Turbulence and Combustion Research Laboratory. He received his Ph.D. in Aerospace Engineering from the University of Michigan in 2005 and was a National Research Council Postdoctoral Fellowship within the Chemistry Division of the Naval Research Laboratory in Washington, D.C. from 2005 to 2008. Subsequently, Prof. Sutton joined the faculty at Ohio State University in 2008. Prof. Sutton’s current research interests include turbulent mixing and combustion, the development and application of advanced laser diagnostics, vaporization and gas-phase mixing in high-pressure turbulent sprays, auto-ignition dynamics, particle-laden flows, energetics, and high-speed propulsion. Prof. Sutton is an Associate Fellow of AIAA, Associate Editor of the Proceedings of the Combustion Institute, a member of the Editorial Board of Combustion and Flame, and author of more than 100 journal and conference publications. He is the recipient of the National Science Foundation CAREER award, the Air Force Office of Scientific Research Young Investigator Program award, the Ohio State University College of Engineering Lumley Research award, the Distinguished Paper award at the 31st International Symposium on Combustion, and two Best Paper awards from AIAA.
