报告题目：
Particle Clustering and Jetting in a Cylindrical Shock Tube
演讲人：
Prof. Fue-Sang Lien
（Department of Mechanical & Mechatronics Engineering University of Waterloo, Canada）
时间：2013年10月22日（周二）上午10:00-11:30
地点：力学所主楼312会议室
邀请人：姜宗林 研究员
报告摘要：
It is widely observed in volcanic eruptions, supernovae and heterogeneous explosive detonation that expansion of condensed-phase particles forms clusters and coherent jets. Detonation of an explosive mixture containing densely-packed bulk liquid or solid particles provides a good approach in studying these dense particle flows inherently with particle clustering and jetting, which are generated at the very early stage of the particle dispersal process, persisting then for a long time. Despite progress to date in both experimental and numerical studies, the true mechanisms causing particle clustering and jetting are still unknown due to the complex phenomena involved in the early phase of expansion, including shock-particle interaction, particle collision and turbulence.
In this talk, a cylindrical shock tube using a packed annular particle bed (also referred to as a "powder bed" herein) placed in the driven section with its far end adjacent to open air is numerically investigated, in order to understand the fundamental phenomena and physical mechanisms associated with the particle clustering and jet structures in the shock-compacting and expanding dense solid flow. Numerical simulations at mesoscale are performed over a range of parameters, including driver gas, particle morphology and distribution, and powder bed configuration.
