Experimental evidence that turbulent evolution can be approximated by recurrent flows
Johns Hopkins University
Abstract
Despite a long and rich history of scientific investigation, fluid turbulence remains one of the most challenging problems in science and engineering. One of the key outstanding questions concerns the role of coherent structures that describe frequently observed patterns embedded in turbulence. It has been suggested, but not proven, that coherent structures correspond to unstable, recurrent solutions of the governing equations of fluid dynamics. In this talk, I will present the first experimental evidence that three-dimensional, weakly turbulent (spatiotemporally chaotic) flow tracks the spatial and temporal structure of multiple such solutions, episodically but repeatedly. These results provide compelling evidence that coherent structures, grounded in the governing equations, can be harnessed to predict how turbulent flows evolve.
About the speaker
Dr. Christopher Crowley is a postdoctoral fellow at Johns Hopkins University, where he works with Prof. Rui Ni studying vortex breakup in stratified flows such as those observed in the ocean. His main research interests are in dynamical systems modeling of complex phenomena such as turbulence and developing novel measurement techniques to provide more information about these systems. Chris started his scientific career at the National Institute of Standards and Technology (NIST) right after graduating from high school. Upon co-authoring his first paper, he matriculated at the University of Maryland (UMD), where he studied both physics and philosophy while continuing to work at NIST. By the time he graduated, Chris authored or coauthored 9 peer-reviewed publications and 2 NIST Special Publications. His research at NIST was focused on flow metrology, but he became increasingly interested in understanding turbulence deterministically. After graduating from UMD, Chris went on to the Georgia Institute of Technology (Georgia Tech), where he received his master’s and PhD in physics, working with Profs. Mike Schatz and Roman Grigoriev on a dynamical systems description of turbulence. In addition to studying turbulence at Georgia Tech, Chris pursued numerous side projects, including developing a technique for simultaneously measuring spatiotemporally-resolved ion and voltage waves in cardiac tissue, studying how Hawk Moths fly, patenting a medical device, and starting a company.
