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From YouTube: SimPEG Meeting Nov 6
Description
Matthias Bücker gives us an overview of his work modelling IP and we explore trajectories for collaborating on IP modelling in SimPEG
A
Or
like
accessible
and
easy
to
use
modeling
tools
after
my
trip.
After
my
talk
and
also
before
and
now
or
during
the
IP
workshop,
the
idea
came
into
the
world
to
provide
like
corresponding
Jupiter
North
notebooks,
based
on
simple
who
make
an
IP
modeling
more
available,
because
I
used
the
COMSOL
multiphysics
modeling
package
and
that's
definitely
not
accessible
for
everybody
in
the
community,
because
it's
quite
expensive
right
and
so
when
say,
oh
we've
contacted
me
and
we
were
looking
for
like
the
first
step
to
do
and
we
decided
to
start
with
a
very
simple
case.
A
A
A
C
A
A
B
A
A
Distribution
of
field
lines
is
caused
by
a
surface
charge
which
builds
up
here
on
the
surface
of
the
particle
little
the
true
surface,
charge
and
true
surface
charge,
for
me
is
the
surface
charge
which
does
not
have
a
geometrical
extension
perpendicular
to
the
pocket
particles
already.
It
is
located
on
a
layer
with
zero
thickness
around
the
surface
right.
C
A
Our
my
objectives
also
always
are:
firstly,
see
what
happens
on
the
micro,
no
sale,
the
micro
scale,
so
visualize,
the
geometry
of
these
diffuse
charge
clouds,
because
they
can
tell
us
about
the
physics
of
the
problem
or
how
how
the
things
configure
and
give
us
a
better
feeling
about
what
happens
on
the
micro
scale.
So
that's
one
issue
or
one
objective
and
the
other
objectives.
A
E
B
A
A
A
Conductivity
and
also
the
permittivity
is
constant.
That's
why
the
electrical
field
has
not
caused
any
charges
to
build
up
and
that's
why
we
can
use
in
a
classic
question
to
describe
the
electrical
potential
within
the
particle
for
the
sake
of
completeness,
and
there
are
no
iron
content
in
or
within
the
particle.
A
Now
the
interesting
part
are
the
equations
in
the
electrolyte,
and
here
we
want
the
ions
to
move
and
to
be
moved
by
diffuse
forces
or
diffuse
fluxes.
That's
this
first
term
here
on
the
left.
On
the
right
hand,
side
is
these:
are
the
the
ind
fugitive
if
you
diffusivities,
sorry,
which
can
be
calculated
from
the
iron
mobilities?
A
Okay
and
all
these
iron
concentrations
are
coupled
to
the
electrical
potential
quietly.
This
I
was
on
equation
right,
where
this
part
simply
is
the
charge
density
and
I
cation
concentrations,
an
ion
concentrations,
multiplied
by
the
Faraday
constant.
If
the
space
charge
of
the
charge-
and
here
we
have
the
permittivity
of
electrolyte.
A
A
G
D
A
A
F
A
A
Essentially,
we
just
in
this
case
we
just
drop
one
term,
so
we
are
left
with
this
final
equation,
where
we
relate
the
perturbation
to
concentrations
of
the
iron
species
and
with
the
gradient
M.
Here
we
only
have
the
power
concentrations,
and
here
the
perturbation
field
of
the
gradient
of
the
perturbation
potential
right.
A
D
F
F
F
B
F
A
The
idea
is
to
model
this
cylindrical
volume,
which
includes
this
spherical
particle
and
because
it's
much
faster
and
and
it's
possible
remember
until
now,
I've
only
am
modeled.
This
2d
domain,
like
with
using
an
appropriate,
coordinate
transformation
and
you
you
can
just
model
it
pooty
right
to
get
this
3d
response
of
this
very
simple
and
symmetrical
I.
F
A
F
F
Okay,
in
our
case,
we
usually
consider
the
top
boundary
when
you've
got
two
boundary
conditions
for
electrical
potential
or
a
life
experience
and
the
currents
right.
That's
usually
the
same
like
it
for
our
case,
but
it
seems
like
it's
a
little
bit
different
here
so
for
the
second
one,
how
are
you
actually
setting
the
boundary?
So
are
you
using
the
kind
of
following
equation
to
set
up
the
boundary
or
it's.
F
G
A
I
A
So
my
domain
size
L,
is
normally
10
times
the
particle
rated
and
the
maximum
element
size
of
these
elements.
Here
in
the
volume
M
is
L
divided
by
20
and
particle
sizes.
Well,
in
this
case,
it's
0.1
millimeter,
but
the
idea
is
to
be
able
to
model
particle
sizes
from
the
micrometer
range
to
the
millimeter
range.
A
Now
here,
I
have
a
very
fine
grid,
minimum
element
and
size
of
P
times
eighty
particle
radius
divided
by
400
and
then
into
the
volume
mesh
or
the
element
size
increases
rapidly
and
on
the
very
boundary
and
comes
all
allows
me
to
define
a
quadrangle
augury
layer,
mass
M,
which
is
on
which
this
part.
These
elements
are
very
long
and.
A
Along
the
boundary,
that's
these
p
times
a
divided
by
400,
but
in
perpendicular
direction.
The
smallest
spacing
is
the
Debye
length
divided
by
2
I've
written
down.
You
need
a
D
by
length
here,
and
so
this
this
is
again
I.
Think
all
these
varieties
are
now
and
the
main
problem
is
that
the
Debye
length
and.
A
The
thickness
of
the
diffuse
layer
normally
or
for
normal
electrolyte
concentrations
is
in
the
range
of
nanometers,
so
10
nanometers,
more
or
less,
and
it
respectively,
from
how
large
the
particle
is.
So
you
can
imagine
that
if
you
want
to
model
the
large
particle-
and
you
have
quite
a
few
scales
between
what
you
have
to
resolve
at
the
particle
surface
and
the
size
of
the
total
domain,
you
have
to
a
model.
A
F
H
H
A
Okay,
I
will
try
to
find
out
what's
happening
there.
So
you,
if
you
don't,
want
to
go
into
much
detail
with
console
you
don't
have
to,
and
normally
only
if
you
encounter
a
problem,
you
start
to
go
deeper
until
the
detail
and
see
where,
where
it
is,
and
maybe
help
comes
or
two
to
make
it
better
a
decision
but
yeah
with
this
mesh
and
like
default
or
automatically
selected
solvers.
It
works
quite
well
I'm
comparison
to
the
analytical
solutions.
F
In
question
Oh
like
that,
so
that's
like
current
merge
is
working
I
guess
and
of
course,
can
you
go
like
to
have
a
relative
good
match
with
your
analytic
solution?
So
let's
say
here
yours
in
eight
layers
of
like
really
thin,
not
sure
what
Quadra
quadrangle
boundary
like
how
horse
can
you
like
sort
of
gold?
Have
you
tried
that
I.
A
Haven't
really
done
that
very
systematic,
but
I
have
tried
to
reduce
the
number
of
small
quadrennial
but
regular,
and
that
made
the
solution
worse.
So
I
did
I
just
use
this
one
yeah
buddy,
but
if
it
helps
you
like
this
comparison
between
the
console
solution
and
your
solution
and
I
could
do
it
a
little
bit
more
systematically.
B
But
question
I
have
is
so
with
respect
to
this
internal
boundary
layer
between
the
particle
and
the
electrolyte.
Are
you
out
imposing
boundary
conditions
there,
or
do
they
come
out
of,
like?
Does
that
naturally
fall
out
of
the
set
of
equations
that
you're
solving
or
you
like?
Do
you
know
what
it
means
you
have
to
actually
go
in
and
change
the
differential
operators.
K
B
F
F
H
Couple
of
time
so
I
mean
what
pens
on
the
elements
that
you're
using
it
could
be
defined
in
different
parts
of
each
element.
Yeah
right,
so
it's
depending
on
see
you
can.
You
can
solve
to
like
a
certain
order
of
accuracy.
You
could
use
like
the
center
point
or
you
could
use
a
point.
That's
like
a
third
of
the
way
down
from
each
side.
There's
different
special
points
inside
the
element
and
you're
I
think
you're
solving
it.
There.
B
I
F
K
K
K
I
B
B
B
K
K
K
K
B
B
B
Yeah
and
then
the
other
thing
we
use
slack
to
communicate
quite
a
bit.
I,
don't
know
if
you've
used
slack
before
so
I
can
send
you
I
can
send
you
a
sign-up
link
if
you're
interested
I
mean
we're
sort
of
always
on
there.
So
it's
a
good
place
to
instant
message
us
and
ping
us,
and
we
can
do
video
calls
and
things
like
that
through
there
too.
So.