报告题目：Fluid turbulence: a physics problem

报 告 人：徐海涛, 金沙总站6165地址

报告时间：2015年11月5日16：00

报告地点：理科楼郑裕彤大讲堂

报告摘要： Most fluid flows we encounter in nature and in technological applications are turbulent. Fluid turbulence occurs because the destabilizing inertial effect overwhelms 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. In fact, fluid turbulence is often called "the last unsolved problem in classic physics". Traditionally, studies of turbulence have 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 the Lagrangian viewpoint, i.e., following ``tracer particles'' that move with the fluid in the turbulent flow field. The new perspective revealed many interesting properties of turbulence and advanced our understanding, but also posed intriguing questions. In this talk, I will review the basic understanding of turbulence (Kolmogorov's 1941 theory) and more recent development, and introduce some interesting problems currently under investigation.