A Lagrangian Analysis of Tip Leakage Vortex in a Low-Speed Axial Compressor Rotor
Symmetry,
Journal Year:
2024,
Volume and Issue:
16(3), P. 344 - 344
Published: March 13, 2024
A
Lagrangian
method
is
introduced
to
analyze
the
tip
leakage
vortex
(TLV)
behavior
in
a
low-speed
axial
compressor
rotor.
The
finite-time
Lyapunov
exponent
(FTLE)
fields
are
calculated
based
on
delayed
detached-eddy
simulation
(DDES)
results
and
identifying
FTLE
ridges
as
coherent
structures
(LCSs).
computational
of
field
three-dimensional
unsteady
flow
discussed
then
applied
instantaneous
at
both
design
near-stall
conditions.
Results
show
that
accuracy
particle
trajectory
density
initial
grid
greatly
affect
and,
thus,
LCSs.
Compared
Eulerian
Q
method,
which
symmetric
anti-symmetric
components
local
velocity
gradient
tensor,
has
great
potential
unraveling
mechanism
complex
structures.
LCSs
transport
barrier
between
TLV
secondary
TLV,
indicating
two
separate
vortices.
aLCSs
bubble-like
bar-like
structure
isosurfaces
corresponding
bubble
spiral
breakdown
patterns.
Language: Английский
Numerical study of separation flows in a U-duct using DDES method
AIP Advances,
Journal Year:
2024,
Volume and Issue:
14(6)
Published: June 1, 2024
Separation
flow
in
a
curved
duct
is
common
phenomenon
engineering
applications,
and
it
highly
contributes
to
the
performance
of
fluid
machinery.
Accurate
prediction
flows
using
computational
dynamics
method
remains
challenge
due
limitations
turbulence
modeling.
Hence,
high-fidelity
delayed
detached
eddy
simulation
(DDES)
approach
employed
simulate
U-duct
with
Reynolds
number
105.
The
DDES
results
are
compared
experimental
data
from
study
by
Monson
et
al.
(1990)
analyzed
detail.
Q-criterion
defined
analyze
vortex
structures
mechanism
separation
region.
Discussions
made
on
characteristics,
including
energy
spectra,
helicity
density,
anisotropy
flow.
Results
indicate
that
regions
near
wall
within
anisotropic.
region
two-dimensional
state,
“rod-like”
state.
Language: Английский