Vortex definition and "vortex criteria"

• 来源期刊: 中国科学:物理学 力学 天文学（英文版）
• 年，卷（期）: 2018,（2）
• 页码范围: 82-86
• 页数: 5页
• 语种: 英文
• DOI: 10.1007/s11433-017-9120-8

摘要

It is well known that the vorticity ω =▽ × u,where u is fluid velocity,has clear mathematic definition,but for viscous flow the definition of a vortex remains an open problem for long [1,2],which has now evolved to a big confusion after many "vortex identification criteria" ("vortex criteria" for short) were proposed to identify various turbulent coherent structures observed experimentally and numerically.The present communication attempts to clarify this confusing situation and provide a preliminary answer to the question:What is a vortex?1)