求是数学前沿讲坛

标题： Superfluid Passing an Obstacle and Vortex Nucleation
报告人：林芳华 教授（美国纽约大学科朗研究所）

报告时间：2018年1月4日 星期四 下午16:00 ---17:00
报告地点：玉泉校区逸夫工商楼4楼

摘要：The problem of a classical compressible and irrotational fluid passing an obstacle was well-
known and studied by many. Roughly speaking,when the velocity of the fluid is small, the flow would be
smooth and nothing much would occur (subsonic regime). When the fluid velocity is very large, there
are shocks and the fluids become rather turbulent and mathematically it is not easy to understand
(supersonic regime). In between, there is a critical speed (at infinity) at which the fluid reach
the maximum speed (sound speed for the fluid) on the boundary of the obstacle.Since a superfluid by
the definition is frictionless, hence it would not develop shocks. On the other hand, formal arguments
imply that the long-wave approximations of superfluid flows (semiclassical limits) would be a
classical flow described by the compressible Euler equations. The latter may develop shocks however. A
natural question is: what would really happen to the superfluid flows, and how one would explain it
then?
Reasonings from physics which are supported by numerical simulations, lead to the phenomena of the
vortex nucleation and the vortex shedding. The aim of this talk is to present some recent rigorous
mathematical analysis on these issues.


欢迎大家参加！
联系人：张挺老师（zhangting79@zju.edu.cn)