报告题目🦸🏻‍♂️：Experimental Investigation of the Lagrangian Properties of Fluid Turbulence

报 告 人：Xu Haitao, Ph.D.

Senior researcher at Max Planck Institute for Dynamics and Self-Organization (MPIDS)

Goettingen, Germany

报告时间👩🏽‍🦰：2013.3.29（周五）, 14:00-16:00

报告地点🧔🏻：杏福娱乐热能系系馆报告厅

主 持 人🫧：姚强

报告简介🛬：Most fluid flows we encounter are turbulent, which occur due to the strong destabilizing inertial effect compared to the smoothing, viscous effect (the ratio of the strength of the two mechanisms is measured by the Reynolds number). To date, despite very impressive progresses in the modeling and controlling of engineering flows, our understanding of the physics of turbulence is still limited. Traditionally, experimental study of turbulence has been almost exclusively in the Eulerian frame, i.e., in a coordinate system fixed in or at a prescribed motion relative to the laboratory frame. The last 15 years witnessed significant development in Lagrangian measurement techniques, i.e., following ``tracer particles'' that move with the fluid in the turbulent flow field. The new perspectives provided from these measurements revealed many interesting properties of turbulence and advanced our understanding, but also posed intriguing questions. In this talk, I will describe the particle tracking technique and the turbulence facilities at Max Planck Institute of Dynamics and Self-Organization (MPIDS), Goettingen, Germany, followed by a report of some recent work on the interesting interplay between vorticity and the rate of strain as revealed by studying the evolution of four fluid tracers.

报告人简介：Ph.D in 2003 from Sibley School of Mechanical and Aerospace Engineering, Cornell University. Ph.D Dissertation on collisional granular flows. From 2003 to 2006, postdoc at Laboratory of Atomic and Solid-State Physics, Cornell University, worked on experimental investigation of fluid turbulence. 2006-present, researcher at Max Planck Institute for Dynamics and Self-Organization (MPIDS, formerly Max Planck Institute for Fluid Dynamics founded by Ludwig Prandtl), Goettingen, Germany. Since 2009, senior researcher (permanent position) at MPIDS. His current research is on the physics of fluid turbulence, with special interest in studying turbulence from the Lagrangian perspective.