报告人: Brian Cantwell（Stanford University）

时间：6月2日（周一）10:00-11:30

地点：新奥工学大楼3F-3048会议室

主持人：谢金翰 助理教授

内容简介：

   It is known that the axisymmetric jet created by an impulsive point force applied to an incompressible viscous fluid is invariant under the dilation group of the Navier Stokes equations. When the problem is formulated in similarity coordinates, the governing equations are reduced from 4 to 3 dimensions and the particle path equations reduce to an autonomous system  with the jet Reynolds number as a parameter. Transition in the phase portrait of particle paths consists of a sequence of bifurcations with two critical Reynolds numbers and three states of motion culminating in the formation of a starting  vortex. The goal of this seminar is to explore the transition process in terms of the trajectory of the flow in the space of invariants of critical points in the particle path vector field. The geometry of the pressure-viscous stress tensor set against this trajectory suggests directions along which the axisymmetric jet might break down and become fully three dimensional. Implications for the high Reynolds number jet will be discussed.

报告人简介：

    Brian Cantwell，美国斯坦福大学航空航天系Edward c,Wells讲席教授，美国国家工程院院士，美国物理学会(APS)会士，美国航空航天学会(AIAA)会士，英国皇家航空学会会士，Sigma Xi科学研究荣誉学会会员。Cantwell教授本科毕业于圣母大学，后在美国宇航局(NASA)约翰逊航天中心参与阿波罗登月计划发动机地面测试。在比利时获得冯·卡门流体力学研究所文凭，随后于加州理工学院获得硕士(1971)和博士(1976)学位，并留校任博士后研究员。自1978年起在斯坦福大学任教，并于2001至2008年担任航空航天系系主任，曾参与多个国家航空发动机项目的技术评估工作。著有专著四部，包括 2002 年由剑桥出版社出版的教科书《Introduction to Svmmetry Analysis》。研究方向包括湍流时空结构的理论、数值和实验方法，混合推进器的边界层燃烧模型，无限雷诺数极限下的壁湍流结构等。

欢迎广大师生光临！