A new vector named Rortex [C. Liu et al., “Rortex—A new vortex vector definition and vorticity tensor and vector decompositions,” Phys. Fluids 30, 035103 (2018)] was proposed to represent the local fluid rotation in our previous work. However, the Galilean invariance of Rortex is yet to be elaborated. In the present study, we prove that Rortex is invariant under the Galilean transformation and several examples are provided to confirm the conclusion.

1.
J.
Jeong
and
F.
Hussain
, “
On the identification of a vortex
,”
J. Fluid Mech.
285
,
69
94
(
1995
).
2.
X.
Dong
,
S.
Tian
, and
C.
Liu
, “
Correlation analysis on volume vorticity and vortex in late boundary layer transition
,”
Phys. Fluids
30
,
014105
(
2018
).
3.
X.
Dong
,
G.
Dong
, and
C.
Liu
, “
Study on vorticity structures in late flow transition
,”
Phys. Fluids
30
,
104108
(
2018
).
4.
J.
Hunt
,
A.
Wray
, and
P.
Moin
, “
Eddies, streams, and convergence zones in turbulent flows
,” Report CTR-S88,
Center For Turbulence Research
,
1988
.
5.
M.
Chong
,
A.
Perry
, and
B.
Cantwell
, “
A general classification of three-dimensional flow fields
,”
Phys. Fluids A
2
,
765
777
(
1990
).
6.
J. H.
Elsas
and
L.
Moriconi
, “
Vortex identification from local properties of the vorticity field
,”
Phys. Fluids
29
,
015101
(
2017
).
7.
C.
Liu
,
Y.
Wang
,
Y.
Yang
, and
Z.
Duan
, “
New omega vortex identification method
,”
Sci. China: Phys., Mech. Astron.
59
,
684711
(
2016
).
8.
B.
Epps
, “
Review of vortex identification methods
,” AIAA Paper 2017-0989,
2017
.
9.
Y.
Zhang
,
X.
Qiu
,
F.
Chen
,
Y.
Zhang
,
X.
Dong
, and
C.
Liu
, “
A selected review of vortex identification methods with applications
,”
J. Hydrodyn.
30
(
5
),
767
779
(
2018
).
10.
Q.
Chen
,
Q.
Zhong
,
M.
Qi
, and
X.
Wang
, “
Comparison of vortex identification criteria for planar velocity fields in wall turbulence
,”
Phys. Fluids
27
,
085101
(
2015
).
11.
Y.
Chashechkin
, “
Visualization and identification of vortex structures in stratified wakes
,” in
Eddy Structure Identification in Free Turbulent Shear Flows
, Fluid Mechanics and Its Applications Vol. 21, edited by
J. P.
Bonnet
and
M. N.
Glauser
(
Springer
,
Dordrecht
,
1993
), pp.
393
403
.
12.
C.
Liu
,
Y.
Gao
,
S.
Tian
, and
X.
Dong
, “
Rortex—A new vortex vector definition and vorticity tensor and vector decompositions
,”
Phys. Fluids
30
,
035103
(
2018
).
13.
S.
Tian
,
Y.
Gao
,
X.
Dong
, and
C.
Liu
, “
Definitions of vortex vector and vortex
,”
J. Fluid Mech.
849
,
312
339
(
2018
).
14.
Y.
Gao
and
C.
Liu
, “
Rortex and comparison with eigenvalue-based vortex identification criteria
,”
Phys. Fluids
30
,
085107
(
2018
).
15.
G.
Haller
, “
An objective definition of a vortex
,”
J. Fluid Mech.
525
,
1
26
(
2005
).
16.
C.
Liu
,
Y.
Yan
, and
P.
Lu
, “
Physics of turbulence generation and sustenance in a boundary layer
,”
Comput. Fluids
102
,
353
384
(
2014
).
You do not currently have access to this content.