Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(10)
Published: Oct. 1, 2023
Airborne
transmission
is
one
of
the
main
modes
for
highly
infectious
diseases
such
as
COVID-19.
Pathogen
laden
aerosols
from
an
infected
person
can
be
transported
by
air
to
a
susceptible
population.
A
widely
used
model
airborne
considers
indoor
space
well-mixed
that
pathogen
concentration
spatially
homogeneous.
Other
models
employ
computational
fluid
dynamics
(CFD)
allow
tracking
spatiotemporal
variation
infection
probability
in
spaces
but
are
computationally
expensive.
Here,
we
compare
predictions
continuously
stirred
tank
reactor
(CSTR)
with
CFD
airflow,
along
Lagrangian
aerosol
particles.
Of
particular
interest
ventilation
using
ceiling
fans,
which
common
South
East
Asia.
It
found
behavior
particles
at
walls
plays
important
role.
Two
limiting
cases
studied:
all
reaching
wall
get
trapped
vs
being
reflected
solid
boundaries.
We
propose
modification
CSTR
equation
include
effect,
and
it
matches
data
closely.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(1)
Published: Jan. 1, 2025
This
paper
investigates
the
transmission
characteristics
of
cough
droplets
from
infected
individuals
in
office
environments
under
influence
an
impinging
jet
ventilation
(IJV)
system
based
on
Eulerian–Lagrangian
model.
The
accuracy
dispersed
phase
model
and
IJV
simulation
was
validated
by
analyzing
a
single
droplet
evaporation
model,
publicly
available
experimental
results,
previously
simulated
results.
effects
different
exhaust
locations,
relative
positioning
to
individual,
application
partitions
spatial
propagation
are
explored.
results
indicate
that
exhibit
significant
ability
obstruct
capture
droplets.
Under
static
conditions,
they
capable
capturing
over
36%
generated
coughing,
although
this
efficiency
may
be
slightly
influenced
system.
notably
affects
movement,
with
progressively
converging
toward
upper-left
corner
room
as
airflow
develops.
exhausts,
combination
system,
is
crucial
impeding
removing
Taking
into
account
variations
individual's
position,
centrally
located
arrangement
might
provide
more
effective
inhibition
virus
dispersion.
Physics of Fluids,
Journal Year:
2024,
Volume and Issue:
36(1)
Published: Jan. 1, 2024
The
use
of
physical
dividers
as
control
measures
for
short-range
viral
transmission
in
indoor
settings
has
gained
increasing
attention.
However,
the
understanding
regarding
their
correct
usage
under
different
seating
arrangements
is
incomplete.
In
this
study,
we
focused
on
assessing
effectiveness
impeding
transient
cough
droplets
three
representative
layouts
using
large-eddy
simulation
technique
with
Eulerian–Lagrangian
model.
We
computationally
also
investigated
effects
ventilation
droplet
desk-divider
layouts.
approach
was
tested
two
rates
(1.0
and
1.8
m/s).
A
comparative
analysis
flow
fields,
topologies,
particle
directions
been
studied.
findings
indicate
that
sitting
arrangements,
rates,
partition
play
a
significant
role
designing
effective
infection
office
setup
considered.
protected
occupied
zone
(POV)
worked
best
situations
low
m/s)
cross-partition
protecting
healthy
persons.
addition,
POV
performed
well
high
(1.8
face-to-face
layout.
side-by-side
configuration
poorly
considered
person
seated
directly
opposite
infected
person.
numerical
predictions
may
be
used
to
validate
other
experimental
studies
educate
workers
engineers
airborne
control.
Physics of Fluids,
Journal Year:
2024,
Volume and Issue:
36(1)
Published: Jan. 1, 2024
The
effects
of
ventilation
strategies
on
mitigating
airborne
virus
transmission
in
a
generic
indoor
space
representative
lobby
area
or
information
desk
found
hotel,
company,
cruise
ship
are
presented.
Multiphase
computational
fluid
dynamics
simulations
employed
conjunction
with
evaporation
modeling.
Four
different
flow
rates
examined
based
the
most
updated
post-COVID-19
pandemic
standards
from
health
organizations
and
recent
findings
research
studies.
Three
air
changes
per
hour
provide
best
option
for
minimizing
droplet
spreading
at
reasonable
energy
efficiency.
Thus,
higher
rate
is
not
solution
to
avoid
diseases.
Simultaneous
coughing
all
occupants
revealed
that
contagious
droplets
could
be
trapped
regions
low
airflow
furniture,
significantly
prolonging
their
time.
can
help
define
reduce
mitigate
while
maintaining
adequate
lower
consumption.
present
work
impacts
how
heat,
air-conditioning,
systems
designed
implemented.
Physics of Fluids,
Journal Year:
2023,
Volume and Issue:
35(10)
Published: Oct. 1, 2023
This
paper
concerns
virus
droplet
simulations
in
a
typical
cruiser's
cabin.
Effects
of
ventilation
rates
and
positions
the
coughing
person
were
investigated.
The
study
also
emphasizes
importance
including
evaporation
models
to
simulate
process
accurately.
A
higher
rate
is
not
always
best
strategy
avoid
spread
airborne
diseases,
as
saliva
droplets
can
further
at
high
rates.
Regardless
strategy,
they
evaporate
faster
than
room's
air
renewal.
One
should
aim
for
minimum
spreading
inside
cabin
different
strategies
occupied
cabins.
authors
propose
using
systems
medium
flow
around
120
m3/h
or
three
changes
per
hour
when
occupied.
value
close
recommended
108
from
latest
standard
by
American
Society
Heating,
Refrigerating
Air-Conditioning
Engineers.
suggested
minimizes
while
maintaining
good
ventilation,
comfort,
energy
consumption.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(2)
Published: Feb. 1, 2025
The
COVID-19
pandemic
highlighted
the
need
for
rapidly
deployable
healthcare
facilities,
leading
to
increased
use
of
modular
construction
methods.
Nonetheless,
knowledge
about
airflow
patterns
and
spread
bioaerosols
in
these
wards
remains
insufficient,
potentially
heightening
risk
cross-infection
among
workers
patients.
This
paper
presents
a
ventilation
design
negative-pressure
ward
aimed
at
reducing
infectious
particles.
We
investigate
effects
various
designs,
patient
postures
(sitting
supine),
air
changes
per
hour
(ACH)
on
cough
droplets
an
airborne
infection
isolation
room
using
large
eddy
simulation
Eulerian–Lagrangian
model.
Findings
show
that
ceiling
exhaust
grilles
(design
2)
resulted
lowest
radial
dispersion
(3.64
m)
12
ACH,
while
sidewall
exhausts
(baseline)
performed
best
higher
ACH
levels.
Seated
patients
had
quicker
droplet
evaporation
compared
those
supine
position.
setups
survival
included
bed's
bottom
ceiling,
maintaining
minimum
ACH.
Cases
5
13,
with
over
patient's
head
bottom,
showed
concentrations
DPM,
under
0.008
km−3
near
source
less
than
0.001
mid-room.
Sitting
posture
consistently
led
lower
DPM
concentrations.
research
emphasizes
critical
role
placement
re-circulation
transmission
risks,
ultimately
contributing
improved
strategies
control
AII
rooms.
Physics of Fluids,
Journal Year:
2025,
Volume and Issue:
37(3)
Published: March 1, 2025
This
study
investigates
the
effect
of
natural
ventilation
on
distribution
airborne
pathogens
in
narrow,
low-ceiling
corridors
typical
hotels,
offices,
or
cruise
ships.
Two
scenarios
are
examined:
a
milder
cough
at
6
m/s
and
stronger
12
m/s.
A
reference
baseline
case
with
no
airflow
is
compared
to
cases
featuring
an
incoming
velocity
1
(3.6
km/h),
examining
differences
dispersal
respiratory
droplets
from
two
individuals
coughing
spaced
5
meters
apart.
Both
direction
airflow,
assuming
one-way
traffic
minimize
pathogen
transmission.
Findings
indicate
that
accelerates
past
door,
exceeding
3
m/s,
gusts
reaching
4
due
interaction
recirculation
zones.
acceleration
affects
droplet
dispersal.
Larger
(>150
μm)
maintain
ballistic
trajectory,
traveling
2–4
m,
potentially
increasing
transmission
risk
but
suggesting
5-m
distancing
policy
could
suffice
for
protection.
Smaller
(<150
μm),
especially
those
<100μm,
spread
extensively
regardless
strength
while
containing
most
viral
mass
overall.
Thus,
alone
insufficient.
The
recommends
additional
safety
measures
be
enforced,
such
as
wearing
masks,
stricter
usage
protocols
by
limiting
corridor
use
one
person
every
20–30
s,
eliminating
when
feasible
effectively
mitigate
risks
environments.
PeerJ,
Journal Year:
2023,
Volume and Issue:
11, P. e16420 - e16420
Published: Nov. 24, 2023
During
the
recent
pandemic
of
COVID-19
(SARS-CoV-2),
influential
public
health
agencies
such
as
World
Health
Organization
(WHO)
and
U.S.
Centers
for
Disease
Control
Prevention
(CDC)
have
favored
view
that
SARS
CoV-2
spreads
predominantly
via
droplets.
Many
experts
in
aerobiology
openly
opposed
stance,
forcing
a
vigorous
debate
on
topic.
In
this
review,
we
discuss
various
proposed
modes
viral
transmission,
stressing
interdependencies
between
droplet,
aerosol,
fomite
spread.
Relative
humidity
temperature
prevailing
determine
rates
at
which
respiratory
aerosols
droplets
emitted
from
an
expiratory
event
(sneezing,
coughing,
etc
.)
evaporate
to
form
smaller
or
aerosols,
experience
hygroscopic
growth.
Gravitational
settling
may
result
contamination
environmental
surfaces
(fomites).
Depending
upon
human,
animal
mechanical
activities
occupied
space
indoors,
viruses
deposited
be
re-aerosolized
(re-suspended)
contribute
can
conveyed
aerial
particulate
matter
dust
allergens.
The
transmission
then
best
viewed
resulting
dynamic
virus
spread
infected
individuals
susceptible
by
physical
states
active
emissions,
instead
current
paradigm
emphasizes
separate
dissemination
droplets,
contaminated
fomites.
To
achieve
optimum
outcome
terms
risk
mitigation
infection
prevention
control
(IPAC)
during
seasonal
peaks,
outbreaks,
pandemics,
holistic
importance
dealing
with
all
interdependent
modalities,
rather
than
focusing
one
modality.
