- May 6, 2019
- 4:00 p.m.
- 100 Hancock Hall
- Dr. Dana Dabiri, University of Washington
- Faculty Host: Dr. Olivier Coutier-Delgosha
Abstract: The dream of experimental fluid dynamicists is to be able to measure complex, three-dimensional turbulent flow fields globally with very high spatial and temporal resolution. While we are still far from fully realizing this dream, significant progress has been made towards this goal during the last three decades. Early quantitative measurement methods using Pitot tubes, Venturi tubes and later measurement methods, such as Hot Wire Anemometry (HWA) and Laser-Doppler Anemometry (LDA), by their nature, were measurement methods that provided instantaneous velocity signals at single-points through time. Early emphasis in turbulence research and its theoretical advancement therefore necessitated a statistical description of turbulent flow fields, which relied heavily upon measurements provided by these single-point measurement techniques. Since the early seventies, the discovery of the existence of three-dimensional coherent structures within turbulent flows using qualitative flow visualization methods (i.e. shadowgraphs, Schlieren systems, dye injection, etc) has been of significant interest for turbulence researchers. While flow visualization techniques have been around since the days of Prandtl, it is only due to the advent of modern imaging, laser, and data acquisition technology has allowed for qualitative flow visualization to become quantitative. These advents have allowed for the development and advancement of are relatively new measurement technique, Particle Image Velocimetry (PIV) and Particle Tracking Velocimetry (PTV) in two dimensions, and more recently in 3 dimensions. Because of its ability to provide global two/three-dimensional kinematic information as well as its ability to map the evolution of coherent structures through time, PIV/PTV has become a powerful tool in studying, understanding, and modeling fluid flow behavior. In this talk, I will describe the particulars of the 3D Particle Tracking Velocimetry method we have developed and touch on some applications in microflows and LES studies.
Biography: Dana Dabiri is Associate Professor at the William E. Boeing Department of Aeronautics & Astronautics at the University of Washington, in Seattle. He received his B.S. in Mechanical Engineering at the University of California, San Diego in 1985; he received his M.S. in Mechanical Engineering at the University of California, Berkeley in 1987; and he received his PhD in Aerospace Engineering at the University of California, San Diego in 1992. He was a Post-doc at Caltech from 1992-1993, and continued at Caltech as a research scientist until the end of 2001. In 2002, he joined the faculty at the William E. Boeing Department of Aeronautics & Astronautics as an Assistant Professor, and was promoted as an Associate Professor in 2009. He serves as an associate editor for the Journal of Visualization since 2009. His work pursues developing novel ways for quantitatively visualizing the movements of fluids. Most recently, Professor Dabiri’s research activities have developed novel implementations of 2D and 3D digital particle tracking velocimetry (2DPTV & 3DPTV) system that allows for high-resolution measurements of fluid flows.