Galilean invariance of Omega vortex identification method

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In the new vortex identification method (Liu et al.2016) to represent the rotation level and capture and visualize the vortices,proposed in our previous study,the independence of the reference frame and the Galilean invariant were not proved.In the present study,the Galilean invariance of the omega vortex identification method is proved and several examples are presented to verify the conclusion.
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