New normalized Rortex/vortex identification method

By Xiangrui Dong, Yisheng Gao, Chaoqun Liu. The Physics of Fluids, 2019

183 citations recorded by the source corpus.

A new vortex identification criterion, named ΩR, is proposed for the normalization of Rortex, using the idea of the Omega method (Ω). ΩR is a normalized function from 0 to 1, which measures the relative rotation strength on the plane perpendicular to the local rotation axis. The advantages of the proposed ΩR method can be summarized as follows: (1) ΩR is from 0 to 1 and can be further used in statistics and correlation analysis as a physical quantity. (2) ΩR can distinguish the rotational vortices from the shear layers, discontinuity structures, and other non-physical structures. (3) ΩR is quite robust and can be always set as 0.52 to capture vortex structures in different cases and at different time steps.A new vortex identification criterion, named ΩR, is proposed for the normalization of Rortex, using the idea of the Omega method (Ω). ΩR is a normalized function from 0 to 1, which measures the relative rotation strength on the plane perpendicular to the local rotation axis. The advantages of the proposed ΩR method can be summarized as follows: (1) ΩR is from 0 to 1 and can be further used in statistics and correlation analysis as a physical quantity. (2) ΩR can distinguish the rotational vortices from the shear layers, discontinuity structures, and other non-physical structures. (3) ΩR is quite robust and can be always set as 0.52 to capture vortex structures in different cases and at different time steps.

Subfields: Computational Mechanics, Mechanical Engineering

View Paper: https://www.semanticscholar.org/paper/5f80f589b95986c2a1c7484c4dcb9c1247c98327