Physics of Plasmas,
Journal Year:
2023,
Volume and Issue:
30(9)
Published: Sept. 1, 2023
We
demonstrate
a
methodology
for
diagnosing
the
multiscale
dynamics
and
energy
transfer
in
complex
HED
flows
with
realistic
driving
boundary
conditions.
The
approach
separates
incompressible,
compressible,
baropycnal
contributions
to
scale-transfer
quantifies
direction
of
these
transfers
(generalized)
wavenumber
space.
use
this
compare
kinetic
(KE)
across
scales
simulations
2D
axisymmetric
vs
fully
3D
laser-driven
plasma
jets.
Using
FLASH
code,
we
model
turbulent
jet
ablated
from
an
aluminum
cone
target
configuration
outlined
by
Liao
et
al.
[Phys.
Plasmas,
26
032306
(2019)].
show
that,
addition
its
well
known
bias
underestimating
hydrodynamic
instability
growth,
modeling
suffers
significant
spurious
energization
bulk
flow
upscale
cascade.
In
2D,
arises
as
vorticity
strain
instabilities
near
jet's
leading
edge
KE
upscale,
sustaining
coherent
circulation
that
helps
propel
farther
(≈25%
3.5
ns)
keep
it
collimated.
3D,
are
absent.
presented
here
may
also
help
inter-model
comparison
validation,
including
future
efforts
alleviate
some
artifacts
highlighted
study.
Nature Communications,
Journal Year:
2022,
Volume and Issue:
13(1)
Published: Sept. 9, 2022
Advent
of
satellite
altimetry
brought
into
focus
the
pervasiveness
mesoscale
eddies
[Formula:
see
text]
km
in
size,
which
are
ocean's
analogue
weather
systems
and
often
regarded
as
spectral
peak
kinetic
energy
(KE).
Yet,
understanding
spatial
scales
has
been
derived
mostly
from
Fourier
analysis
small
"representative"
regions
that
cannot
capture
vast
dynamic
range
at
planetary
scales.
Here,
we
use
a
coarse-graining
method
to
analyze
much
larger
than
what
had
possible
before.
Spectra
spanning
over
three
decades
length-scales
reveal
Antarctic
Circumpolar
Current
global
extra-tropical
circulation,
≈
104
km,
previously
unobserved
power-law
scaling
103
km.
A
smaller
exists
300
associated
with
mesoscales,
which,
due
their
wider
spread
wavenumber
space,
account
for
more
50%
resolved
surface
KE
globally.
Seasonal
cycles
exhibit
characteristic
lag-time
40
days
per
octave
such
both
hemispheres,
102
peaks
spring
while
late
summer.
These
results
provide
new
window
multiscale
oceanic
circulation
within
Earth's
climate
system,
including
largest
Journal of Advances in Modeling Earth Systems,
Journal Year:
2023,
Volume and Issue:
15(6)
Published: June 1, 2023
Abstract
We
expand
on
a
recent
determination
of
the
first
global
energy
spectrum
ocean's
surface
geostrophic
circulation
(Storer
et
al.,
2022,
https://doi.org/10.1038/s41467-022-33031-3
)
using
coarse‐graining
(CG)
method.
compare
spectra
from
CG
to
those
spherical
harmonics
by
treating
land
in
manner
consistent
with
boundary
conditions.
While
two
methods
yield
qualitatively
domain‐averaged
results,
are
too
noisy
at
gyre‐scales
(>1,000
km).
More
importantly,
inherently
and
cannot
provide
local
information
connecting
scales
currents
geographically.
shows
that
extra‐tropics
mesoscales
(100–500
km)
have
root‐mean‐square
(rms)
velocity
∼15
cm/s,
which
increases
∼30–40
cm/s
locally
Gulf
Stream
Kuroshio
∼16–28
ACC.
There
is
notable
hemispheric
asymmetry
mesoscale
energy‐per‐area,
higher
north
due
continental
boundaries.
estimate
≈25%–50%
total
smaller
than
100
km,
un(der)‐resolved
pre‐SWOT
satellite
products.
Spectra
time‐mean
show
most
its
(up
70%)
resides
stationary
eddies
characteristic
(<500
This
highlights
preponderance
“standing”
small‐scale
structures
ocean
temporally
coherent
forcing
By
space
time,
we
compute
spatio‐temporal
AVISO
NEMO.
These
every
length‐scale
evolves
over
wide
range
time‐scales
peak
≈200
km
≈2–3
weeks.
Physical Review Research,
Journal Year:
2023,
Volume and Issue:
5(4)
Published: Oct. 9, 2023
This
article
uses
magnetic
Rayleigh-Taylor
instability
in
relativistic
collisionless
plasma
as
an
example
of
astrophysical
process
for
nonthermal
particle
acceleration,
and
uncover
the
onset
large-scale
plumes
formed
by
accumulation
small
ones
via
particle-in-cell
simulations.
is
posed
a
potential
mechanism
flares.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(1)
Published: Jan. 1, 2025
The
analysis
of
kinetic
energy
spectrum
and
dissipation
mechanisms
plays
a
crucial
role
in
both
theoretical
examination
real-world
implementations
within
compressible
turbulent
flows.
previous
works
the
near-dissipation
range
are
conducted
framework
incompressible
flow
dynamics.
We
investigate
transfer
isotropic
flows
via
highly
resolved
direct
numerical
simulations
with
different
Mach
numbers
(Mt).
found
that
flows,
model
is
significantly
influenced
by
number,
more
pronounced
tail
as
number
increases.
Within
range,
there
exist
strong
local
spatial
fluctuations
flux
increase
grid
resolution.
viscous
can
be
decomposed
into
solenoidal
dilatational
components,
its
component
leads
to
stronger
intermittency
range.
Besides,
high
also
dissipation,
which
serves
an
alternative
factor
for
uncovered
provides
foundation
prediction
intense
events
development
modelings.
Journal of Renewable and Sustainable Energy,
Journal Year:
2025,
Volume and Issue:
17(1)
Published: Jan. 1, 2025
We
expand
on
the
method
of
sequential
filtering
for
calculating
spectra
inhomogeneous
fields.
Sadek
and
Aluie
[Phys.
Rev.
Fluids
3,
124610
(2018)]
showed
that
kernel
has
to
have
at
least
p
vanishing
moments
extract
a
power-law
spectrum
k−α
with
α<p+2
by
low-pass
filtering.
Here,
we
show
high-pass
allows
extracting
steeper
α<2p+3
using
same
pth
order
kernel.
For
example,
field
is
shallower
than
k−5
can
be
extracted
any
first-order
such
as
Gaussian
or
top-hat.
Finally,
demonstrate
how
second-order
structure
function
fails
capture
spectral
peaks
because
it
cannot
detect
scaling
too
shallow.
Journal of Fluid Mechanics,
Journal Year:
2025,
Volume and Issue:
1003
Published: Jan. 24, 2025
In
this
paper,
we
study
the
rapid
transition
in
Richtmyer–Meshkov
instability
(RMI)
with
reshock
through
three-dimensional
double-layer
swirling
vortex
rings.
The
RMI
has
an
essential
influence
on
evolution
of
supernovas
and
ignition
inertial
confinement
fusion,
which
been
confirmed
numerical
simulations
experiments
shock-tube
high-energy-density
facilities
over
past
few
years.
Vortex
to
dominate
late-time
nonlinear
development
perturbed
interface.
However,
studies
have
investigated
characteristics
interactions
among
structures
during
turbulent
flows.
coexistence
co-rotating
counter-rotating
vortices
is
hypothesized
induce
successive
large-scale
strain
fields,
are
main
driving
sources
for
development.
effect
reflected
presence
local
motion
azimuthal
direction,
it
decreases
translation
velocity
a
ring.
Large-,
middle-
small-scale
fields
employed
describe
process
reshock,
e.g.
vorticity
deposited
by
formation
vortices,
iterative
cascade
under
amplification
viscous
dissipation
internal
energy.
This
provides
theoretical
suggestions
designing
practical
applications,
such
as
estimation
hydrodynamic
mixing
acceleration
phase
fusion.
Nature Communications,
Journal Year:
2025,
Volume and Issue:
16(1)
Published: Jan. 30, 2025
Abstract
Ocean
weather
comprises
vortical
and
straining
mesoscale
motions,
which
play
fundamentally
different
roles
in
the
ocean
circulation
climate
system.
Vorticity
determines
movement
of
major
currents
gyres.
Strain
contributes
to
frontogenesis
deformation
water
masses,
driving
much
mixing
vertical
transport
upper
ocean.
While
recent
studies
have
shown
that
interactions
with
atmosphere
damp
ocean’s
vortices
O
(100)
km
size,
effect
winds
on
motions
remains
unexplored.
Here,
we
derive
a
theory
for
wind
work
vorticity
strain.
Using
satellite
model
data,
discover
damps
strain
at
an
equal
rate
globally,
unveil
striking
asymmetries
based
their
polarity.
Subtropical
oceanic
cyclones
energize
anticyclones
outside
strong
current
regions,
while
subpolar
opposite
effect.
A
similar
pattern
emerges
strain,
where
subtropical
convergent
flow
is
damped
along
west-equatorward
east-poleward
direction
energized
east-equatorward
west-poleward
direction.
These
findings
reveal
energy
pathways
through
shapes
weather.
