应机械结构强度与振动国家重点实验室Marie-Jean THORAVAL教授的邀请，普林斯顿大学的Wouter MOSTERT博士来访我院并作学术报告：
Title: Shock singularities and interface interactions in gas dynamics and magnetohydrodynamics
Speaker: Wouter MOSTERT, Postdoctoral research associate, Department of Mechanical and Aerospace Engineering of Princeton University
Time: Wednesday 20th of March 2019, 10:00 am to 12:00 am
Location: 2nd meeting room (South second floor), School of Aerospace, Xi'an Jiaotong University
Abstract:
Shock waves play a strong role in energy, aerospace and astrophysical applications. Very often in these applications, the medium of propagation for the shock is strongly electrically conductive and may be modelled as a plasma and, in the right circumstances, with magnetohydrodynamics (MHD). As a result, understanding the physics of MHD shock waves and how they interact with density interfaces, as in the well-known Richtmyer-Meshkov instability, is crucial for modelling the processes involved in this diverse array of physical situations. In this talk I will firstly present topics outlining some basic properties of shocks in MHD and the behaviour of the MHD Richtmyer-Meshkov instability. In particular, MHD shocks feature the property of supporting jumps in those components of momentum and magnetic field in directions locally tangential to the shock, resulting in their role as vorticity carriers in shock-interface interactions. This property plays a central part in the ultimate suppression of Richtmyer-Meshkov instability. Secondly, just like gas-dynamic shocks, MHD shocks themselves can be modelled in two or more dimensions using geometrical shock dynamics (GSD), a semi-analytical technique that well approximates shock motion in space. Finally, using insights gained from numerical GSD, it is possible to show that planar and imploding gas-dynamic shocks, and a certain class of MHD shocks, are guaranteed to form triple points at finite times from smooth initial perturbations, drawing allusions to the cellular structures visible in detonation waves.
Biography:
Wouter Mostert is a postdoctoral research associate in the Deike Lab at the Department of Mechanical and Aerospace Engineering of Princeton University. He received his PhD at the University of Queensland in Mechanical Engineering under Vincent Wheatley and has worked as a postdoctoral scholar in the Graduate Aerospace Laboratories at Caltech. His research interests include analysis and simulation of the nonlinear dynamics of shock waves and interfacial instabilities in gases and magnetized plasmas, and have recently expanded to include ocean waves and bubble dynamics. Wouter is the recipient of the student oral presentation award for the 29th International Symposium on Shock Waves (ISSW29, 2013) and is a medalist at the University of Queensland.
