4 / 2019-04-14 09:23:21

Numerical Tests of Liutex(Rortex) Application for Vortex Identification Based on DNS Results

Vortex;,DNS,LIUTex;,Rortex,Swirling,Wake

Applications of Liutex(Rortex) (R method) for vortex identification in swirling/wake flows are numerically tested based on the DNS results. Different vortex identification methods, e.g. vorticity, lamba_2, Q, omega and R methods, are used to identify the vortex structure/core. The DNS results of swirling/wake flows are used herein as the DNS database. The fluid particle's acceleration and its correlation with the vortex identification methods have been analyzed. It is seen that the R method is advantageous over other methods for vortex identification although the Q method is also sufficiently good. The geometrical configuration between fluid particle’ acceleration and R vector is shown. This is a clear and exclusive feature of the R method which the vorticity does not have, and can be used to explain the mechanisms of vortex motion.