of 1
12
th
Cavitation
Symposium
Maich
Conference
Centre,
Chania,
Greece
2-5
June
2024
A
phase
change
model
for
the
simulation
of
cavitating
droplet
aerobreakup
using
interface-capturing
schemes
1
Jose
Rodolfo
Chreim*;
2
Mauro
Rodriguez
Jr;
2
Tim
Colonius;
1
California
Institute
of
Technology
2
Brown
University
ABSTRACT
Interface-capturing
schemes
are
well
established
for
multi-component,
immiscible
flows,
but
simulating
phase
changing
flows
is
yet
a
challenge.
For
an
N
-component
system
including
reacting
liquid
and
vapor
states
of
one
of
the
materials,
we
adopt
the
so-called
six-equation
model
with
source
terms
that
account
for
mechanical,
thermal,
and
chemical
disequilibrium
furnished
with
an
infinitely
fast
relaxation
procedure
[1].
We
solve
the
governing
equations
with
our
validated,
GPU-enabled,
open-source,
high-order
-accurate
flow
solver
called
MFC
[2],
in
which
the
relaxation
process
towards
equilibrium
is
simplified,
for
fluids
obeying
the
stiffened
gas
equation
of
state,
to
finding
the
roots
of
a
2
×
2
system
of
nonlinear
equations.
Numerical
experiments
have
been
performed
for
a
variety
of
test
cases,
and
agreed
well
with
previous
work
[1],
but
there
are
still
challenging
simulations
of
interest
in
academia
and
industry
,
such
as
single
bubble
dynamics
and
aero-droplet
breakup
problems
in
which
phase
change
plays
an
important
role.
For
the
latter,
recent
literature
has
shown
that,
when
subject
to
a
sufficiently
strong
shock,
internally
reflected
rarefaction
waves
can
focus
and
induce
cavitation
[3].
We
managed
to
reproduce
this
behavior
,
generating
vapor
at
the
focal
point,
but
the
results
are
yet
preliminary
and
better
criteria
for
both
triggering
the
model
and
sustaining
the
newly
generated
mixture
region
must
be
established,
since
the
results
depend
on
the
sensibility
of
the
current
criteria.
Additionally
,
phase
change
was
observed
at
locations
that
are
known
not
to
happen.
Therefore,
in
this
presentation
we
intend
to
discuss
modifications
to
our
model
so
it
can
capture
and
sustain
phase
change
at
the
expected
locations,
in
accordance
with
both
theoretical
and
experimental
observations.
We
will
focus
on
presenting
results
for
droplet
aerobreakup
problems
with
induced
cavitation.
[1]
M.
Pelanti,
Arbitrary-rate
relaxation
techniques
for
the
numerical
modeling
of
compressible
two-phase
flows
with
heat
and
mass
transfer
,
Int.
Journal
of
Multiphase
Flow,
153
pp.
104097,
2022.
[2]
S.
H.
Bryngelson
et
al.,
MFC:
An
open-source
high-order
multi-component,
multi-phase,
and
multi-scale
compressible
flow
solver,
Compu.
Phys.
Comm.,
266,
pp.
107396,
2021.
[3]
L.
Biasiori-Poulanges,
H.
El-Rabii,
Shock-induced
cavitation
and
wavefront
analysis
inside
a
water
droplet.
Physics
of
Fluids
33,
097104,
2021.