IntechOpen eBooks,
Journal Year:
2023,
Volume and Issue:
unknown
Published: Dec. 4, 2023
Vortex
definition
and
identification
are
extremely
important
for
the
study
of
fluid
dynamics
research.
Liutex
is
a
newly
proposed
concept
that
correctly
represents
vortex.
vector
whose
direction
local
rotation
axis
magnitude
twice
angular
speed.
To
identify
unique
structure
vortex,
method
known
as
Core
Line
has
been
developed,
which
displays
rotational
core
However,
original
manual
method,
not
practical
real
application,
an
automatic
algorithm
required
usage.
Xu
et
al.
by
selecting
best
line
from
group
candidate
lines,
progress.
In
this
chapter,
another
perspective
to
solve
problem,
new
introduced
based
on
forward
gradient
lines.
Since
lines
have
feature
they
advance
maximums,
route
will
still
result
in
line,
avoids
process
find
line.
This
achieved
some
success
Lambda
vortex
early
boundary
layer
transition.
Journal of Fluids Engineering,
Journal Year:
2022,
Volume and Issue:
145(1)
Published: Sept. 13, 2022
Abstract
This
study
investigates
the
turbulent
flow
properties
experimentally
in
vicinity
of
two
side-by-side
circular
cylinders,
along
with
influence
third
cylinder
same
dimension
placed
upstream
and
successively
downstream
forming
an
equilateral
triangle.
Three-dimensional
stereoscopic
particle
image
velocimetry
(PIV)
was
employed
to
collect
instantaneous
velocity
data
around
arrangements.
The
highlights
prime
parameters
turbulence
such
as
mean
velocities,
Reynolds
stresses,
kinetic
energy
(TKE),
quadrant
analysis,
Q-criteria
for
vortices,
which
are
responsible
development
various
problems
scour-hole
cylindrical
pier
arrangements,
disturbance
industrial
marine
structures.
spectral
analysis
performed
examine
distributions,
vortex-shedding
frequencies
corresponding
Strouhal
numbers.
Dominant
vorticity
locations
were
identified
from
contours
Q-criteria.
magnitude
characteristics
reduced
by
15–20%
(turbulence
intensity
20%
TKE
15%)
when
group.
Streamlines
also
studied
visualize
patterns
a
better
understanding
physics
presence
cylinder.
maximum
vortices
obtained
spectrum
showed
that
generated
less
is
upstream.
The
vortex
structures
in
a
draft
tube
of
Francis
turbine
are
confused,
primarily
when
cavitation
occurs,
which
may
induce
severe
vibration
and
noise.Understanding
this
vortex's
periodical
precession
investigating
the
rope
influence
cone
is
required
for
stable
operation
at
off-design
conditions.This
study
captured
cavitating
flow
with
high
accuracy
by
utilizing
SST
turbulence
ZGB
models.The
Omega
Liutex
methods
employed
compared
traditional
Q
-criterion
to
determine
behavior
Francis-99
tube.The
result
showed
that
Liutex/Rortex
method
advantageous
over
representing
structure.The
can
effectively
remove
boundary
layer's
on
visual
from
tube's
wall.Moreover,
local
hydraulic
loss
distribution
was
clarified
using
entropy
production.By
comparing
magnitude
production
rate,
effects
were
significantly
illuminated.
