Changes
Page history
Update 3.1 Code basics
authored
Jan 10, 2021
by
Udo Ziegler
Hide whitespace changes
Inline
Side-by-side
3-NIRVANA-user-guide/3.1-Code-basics.md
View page @
dad0c042
...
...
@@ -412,7 +412,7 @@ where
is the grid spacing of the base level, i.e., there is a doubling of
resolution from one refinement level to the next higher.
Starting on the base level (
*l*
=
0) mesh refinements are realized by
Starting on the base level (
*l*
=
0) mesh refinements are realized by
overlaying child grid blocks at locations which need refinement
according to different refinement criteria discussed in more detail
below. A child grid block covers one octant (a logical cube of 2 grid
...
...
@@ -432,7 +432,7 @@ The criterion is applied to primary (or related) physical variables
computed along various spatial directions. The switch
*α*
∈
\[
0, 1
\]
(code parameter:
`_C.amr_d1`
) selects between a purely
gradient-based criterion (
*α*
=1) and a purely
second-derivatives-based criterion (
*α*
=
0).
second-derivatives-based criterion (
*α*
=
0).
*U*
<sub>
*r**e**f*
</sub>
are reference values to avoid division by
zero for indefinite variables. The exponent
*ξ*
∈
\[
0, 2
\]
(code
parameter:
`_C.amr_exp`
) introduces a power law functional on the
...
...
@@ -458,7 +458,7 @@ The criterion is applied to primary (or related) physical variables
*c*
<sub>
*s*
</sub>
the sound speed and
*G*
the gravitational
constant, and where
*δs*
= min {
*δx*
,
*h*
<sub>
*y*
</sub>
*δy*
,
*h*
<sub>
*z*
</sub>
*δz*
}.
ℰ
<sub>
*J
**e**a**n**
s*
</sub>
is a user-specific threshold with the
ℰ
<sub>
*J
ean
s*
</sub>
is a user-specific threshold with the
reciprocal value giving the minimum number of grid cells the local
Jeans length should be resolved.
...
...
@@ -467,7 +467,7 @@ The criterion is applied to primary (or related) physical variables

where the first factor is the Field length with
*L*
(𝜚,
*T*
) the
density- and temperature-dependent heatloss function and
*κ*
the
thermal conduction coefficient. ℰ
<sub>
*F
**i**e**l**
d*
</sub>
is a
thermal conduction coefficient. ℰ
<sub>
*F
iel
d*
</sub>
is a
user-specific threshold with the reciprocal value giving the minimum
number of grid cells the Field length should be resolved.
...
...
...
...