Visualizing Liutex Core Using Liutex Lines and Tubes

Liutex is a vortex identification method which can be used to determine the absolute and relative strength of a vortex, the local rotation axis of a vortex, the vortex core center, the size of the vortex core, and the vortex boundary. A vortex core is defined as a concentration of Liutex vectors. It would be nice if we could visualize the Liutex core to gain a better understanding. In this paper, we will use the Liutex core lines and Liutex tubes to show the vortex structure by using pre-processed DNS data, which can help researchers studying fluid dynamics understand the turbulence physics. There is no reason to believe iso-surfaces can represent vortex structure, but it is more reasonable to demonstrate the vortex structures by using the Liutex core lines and Liutex tubes as Liutex is a new vector quantity to represent flow rotation or vortex.