| ... | ... | @@ -415,12 +415,10 @@ possible values or a numeric range. |
|
|
|
Jeans-length-based mesh refinement criterion allowing a
|
|
|
|
systematic reduction of the Jeans threshold with increasing
|
|
|
|
refinement level $l$ according to the expression
|
|
|
|
Jeans length becomes gradually higher resolved with increasing $l$.
|
|
|
|
`_C.amr_dJeans` must be positiv. $y=10^{-7}$ $y=10^{-7}$
|
|
|
|
|
|
|
|
`_C.amr_Jeans`$-l*$`_C.amr_dJeans`, i.e., the local
|
|
|
|
Jeans length becomes gradually higher resolved with increasing $l$.
|
|
|
|
`_C.amr_dJeans` must be positiv.
|
|
|
|
|
|
|
|
$y=10^{-7}$
|
|
|
|
**Important**: `_C.amr_dJeans` must be chosen with care such
|
|
|
|
that the actual Jeans threshold never becomes too small or
|
|
|
|
negative at some refinement level. Otherwise it will trigger
|
| ... | ... | @@ -454,7 +452,6 @@ possible values or a numeric range. |
|
|
|
- `06` (`_C.flag[0-7]`)
|
|
|
|
|
|
|
|
- `_C.flag[0-7]`: freely usable parameter of `int` type.
|
|
|
|
$y=10^{-7}$
|
|
|
|
|
|
|
|
**SOLVER SPECIFICATIONS**:
|
|
|
|
|
| ... | ... | @@ -540,7 +537,7 @@ possible values or a numeric range. |
|
|
|
- `_C.reactions_max_changeX` (typical value: $<0.1$): allowed
|
|
|
|
maximal relative change of species number densities (or total
|
|
|
|
number density) in the time integration of the chemo-thermal
|
|
|
|
rate equations. $y=10^{-7}$
|
|
|
|
rate equations.
|
|
|
|
|
|
|
|
**Important:** The macro `SXN` in module `solveNCCM.c` is a
|
|
|
|
linear weight applying `_C.reactions_max_change` to a combined
|
| ... | ... | @@ -580,8 +577,8 @@ possible values or a numeric range. |
|
|
|
from the momentum equation and the induction equation is not
|
|
|
|
solved.
|
|
|
|
|
|
|
|
- `_C.permeability_rel`: relative magnetic permeability
|
|
|
|
$\mu_{rel}$ ($=\mu/\mu_0,\,\mu_0=4\pi\cdot10^{-7}\mathtt{V}\cdot\mathtt{m}^{-1}\cdot\mathtt{A}^{-1}\cdot\mathtt{s}^{-1}$).
|
|
|
|
- `_C.permeability_rel`: relative magnetic permeability $\mu_{rel}$
|
|
|
|
($=\mu/\mu_0,\,\mu_0=4\pi\cdot10^{-7}\mathtt{V}\cdot\mathtt{m}^{-1}\cdot\mathtt{A}^{-1}\cdot\mathtt{s}^{-1}$).
|
|
|
|
|
|
|
|
**Important:** The Gaussian unit system can be mimicked by
|
|
|
|
choosing a value ${\tt \_C.permeability\_rel}=10^7$ so that
|
| ... | ... | @@ -623,7 +620,7 @@ possible values or a numeric range. |
|
|
|
`_C.conduction_coeff` (and `_C.conduction_coeff_perp` in the
|
|
|
|
anisotropic case) described below. U enables thermal conduction
|
|
|
|
with a user-defined conduction coefficient as coded in the user
|
|
|
|
interface function **conductionCoeffUser()** (cf. [Thermal
|
|
|
|
interface function `conductionCoeffUser()` (cf. [Thermal
|
|
|
|
conduction](#thermal-conduction)). S enables thermal conduction
|
|
|
|
using the standard Spitzer conductivity model predefined in
|
|
|
|
NIRVANA (cf. [physics
|
| ... | ... | @@ -650,8 +647,7 @@ possible values or a numeric range. |
|
|
|
described below. U enables ambipolar diffusion with a
|
|
|
|
user-defined anbipolar diffusion coefficient as coded in the
|
|
|
|
user interface function **APdiffusionCoeffUser()** (cf.
|
|
|
|
[Ambipolar
|
|
|
|
diffusion](#user-defined-coefficient-for-ambipolar-diffusion)).
|
|
|
|
[Ambipolar diffusion](#user-defined-coefficient-for-ambipolar-diffusion)).
|
|
|
|
N disables ambipolar diffusion.
|
|
|
|
|
|
|
|
- `_C.APdiffusion_coeff`: constant ambipolar diffusion
|
| ... | ... | @@ -731,8 +727,8 @@ possible values or a numeric range. |
|
|
|
adiabatic index is not a freely selectable parameter but is
|
|
|
|
approximated by the expression
|
|
|
|
|
|
|
|
$\gamma=\left[5(n_\mathrm{H}+n_\mathrm{He}+n_\mathrm{e})+7n_{\mathrm{H}_2}\right]
|
|
|
|
/\left[3(n_\mathrm{H}+n_\mathrm{He}+n_\mathrm{e})+5n_{\mathrm{H}_2}\right]$.
|
|
|
|
$$\gamma=\left[5(n_\mathrm{H}+n_\mathrm{He}+n_\mathrm{e})+7n_{\mathrm{H}_2}\right]
|
|
|
|
/\left[3(n_\mathrm{H}+n_\mathrm{He}+n_\mathrm{e})+5n_{\mathrm{H}_2}\right]$$.
|
|
|
|
|
|
|
|
- `_C.polytropic_constant`: polytropic constant in the polytropic
|
|
|
|
EOS.
|
| ... | ... | @@ -815,10 +811,10 @@ energy density $e$ is irrelevant since no energy equation is solved. In |
|
|
|
HD simulations, the assignment of the magnetic field is redundant, of
|
|
|
|
course, and would lead to an error because arrays for the magnetic field
|
|
|
|
components are not allocated in the HD case. Likewise, arrays for tracer
|
|
|
|
and species, $C_\mc$ and $n_\ms$, are not declared unless the parameters
|
|
|
|
and species, $C_c$ and $n_s$, are not declared unless the parameters
|
|
|
|
`_C.tracer`$>0$ respective ${\tt\_C.species}>0$. If the TESTFIELDS
|
|
|
|
infrastructure is used (`_C.testfields`$>0$) testfields fluctuation
|
|
|
|
variables, $\mathbf{b}_\mt,\,\mt=0,{\tt\_C.testfields}-1$, are also
|
|
|
|
variables, $\mathbf{b}_t,\,t=0,{\tt\_C.testfields}-1$, are also
|
|
|
|
considered as primary variables and must be assigned by the user. The
|
|
|
|
parameter `_C.testfields` denotes the number of testfields.
|
|
|
|
|
| ... | ... | @@ -851,7 +847,7 @@ structure](#mesh-data-structure). |
|
|
|
|
|
|
|
There are two types of mesh variables: cell-averaged variables and
|
|
|
|
face-averaged variables. Cell-averaged variables are
|
|
|
|
$\varrho,m_x,m_y,m_z,n_\ms,C_\mc$. It are described by cell-centroid
|
|
|
|
$\varrho,m_x,m_y,m_z,n_s,C_c$. It are described by cell-centroid
|
|
|
|
coordinates. Face-averaged variables are the magnetic field components
|
|
|
|
$B_x,B_y,B_z$ (and testfields). It are described by cell face-centroid
|
|
|
|
coordinates.
|
| ... | ... | @@ -950,13 +946,13 @@ divergence-free setup: |
|
|
|
components by exact integration of given analytical expressions. For a
|
|
|
|
grid cell (,,) on superblock `g` the discretized components would then
|
|
|
|
read
|
|
|
|
$$\mathtt{g->bx[iz][iy][ix]}=\frac{1}{\d \mathcal{A}_x}\int
|
|
|
|
$$\mathtt{g->bx[iz][iy][ix]}=\frac{1}{\delta \mathcal{A}_x}\int
|
|
|
|
\limits_\mathtt{g->y[iy]}^\mathtt{g->y[iy+1]}
|
|
|
|
\int\limits_\mathtt{g->z[iz]}^\mathtt{g->z[iz+1]} B_x(\mathtt{g->x[ix]},y,z)h_yh_zdydz$$
|
|
|
|
$$\mathtt{g->by[iz][iy][ix]}=\frac{1}{\d \mathcal{A}_y}\int
|
|
|
|
$$\mathtt{g->by[iz][iy][ix]}=\frac{1}{\delta \mathcal{A}_y}\int
|
|
|
|
\limits_\mathtt{g->x[ix]}^\mathtt{g->x[ix+1]}
|
|
|
|
\int\limits_\mathtt{g->z[iz]}^\mathtt{g->z[iz+1]} B_y(x,\mathtt{g->y[iy]},z)h_zdxdz$$
|
|
|
|
$$\mathtt{g->bz[iz][iy][ix]}=\frac{1}{\d \mathcal{A}_z}\int
|
|
|
|
$$\mathtt{g->bz[iz][iy][ix]}=\frac{1}{\delta \mathcal{A}_z}\int
|
|
|
|
\limits_\mathtt{g->x[ix]}^\mathtt{g->x[ix+1]}
|
|
|
|
\int\limits_\mathtt{g->y[iy]}^\mathtt{g->y[iy+1]} B_z(x,y,\mathtt{g->z[iz]})h_ydxdy$$
|
|
|
|
where the numerical expressions for the cell faces are:
|
| ... | ... | @@ -974,23 +970,23 @@ integration over cell faces turns out to be too complicated. |
|
|
|
The face-averaged magnetic field components are then obtained from the
|
|
|
|
integral form of $\mathbf{B}=\nabla\times \mathbf{A}$:
|
|
|
|
|
|
|
|
`g->bx[iz][iy][ix]`$=\left[h_y\Delta_\miy (h_{zy}\hat{A}_z)
|
|
|
|
-h_y\Delta_\miz \hat{A}_y\right]/\d \mathcal{A}_x$
|
|
|
|
`g->bx[iz][iy][ix]`$=\left[h_y\Delta_{iy} (h_{zy}\hat{A}_z)
|
|
|
|
-h_y\Delta_{iz} \hat{A}_y\right]/\delta \mathcal{A}_x$
|
|
|
|
|
|
|
|
`g->by[iz][iy][ix]`$=\left[\Delta_\miz \hat{A}_x
|
|
|
|
-h_{zy}\Delta_\mix (h_y\hat{A}_z)\right]/\d \mathcal{A}_y$
|
|
|
|
`g->by[iz][iy][ix]`$=\left[\Delta_{iz} \hat{A}_x
|
|
|
|
-h_{zy}\Delta_{ix} (h_y\hat{A}_z)\right]/\delta \mathcal{A}_y$
|
|
|
|
|
|
|
|
`g->bz[iz][iy][ix]`$=\left[\Delta_\mix (h_y\hat{A}_y)
|
|
|
|
-\Delta_\miy \hat{A}_x\right]/\d \mathcal{A}_z$
|
|
|
|
`g->bz[iz][iy][ix]`$=\left[\Delta_{ix} (h_y\hat{A}_y)
|
|
|
|
-\Delta_{iy} \hat{A}_x\right]/\delta \mathcal{A}_z$
|
|
|
|
|
|
|
|
where the difference operators $\Delta_\mix$, $\Delta_\miy$ and
|
|
|
|
$\Delta_\miz$ are given by
|
|
|
|
where the difference operators $\Delta_{ix}$, $\Delta_{iy}$ and
|
|
|
|
$\Delta_{iz}$ are given by
|
|
|
|
|
|
|
|
$\Delta_{\mix}X=X(\mathtt{ix+1,iy,iz})-X(\mathtt{ix,iy,iz})$,
|
|
|
|
$\Delta_{ix}X=X(\mathtt{ix+1,iy,iz})-X(\mathtt{ix,iy,iz})$,
|
|
|
|
|
|
|
|
$\Delta_{\miy}X=X(\mathtt{ix,iy+1,iz})-X(\mathtt{ix,iy,iz})$,
|
|
|
|
$\Delta_{iy}X=X(\mathtt{ix,iy+1,iz})-X(\mathtt{ix,iy,iz})$,
|
|
|
|
|
|
|
|
$\Delta_{\miz}X=X(\mathtt{ix,iy,iz+1})-X(\mathtt{ix,iy,iz})$
|
|
|
|
$\Delta_{iz}X=X(\mathtt{ix,iy,iz+1})-X(\mathtt{ix,iy,iz})$
|
|
|
|
|
|
|
|
and $(\hat{A}_x,\hat{A}_y,\hat{A}_z)$ are the cell-edge integrals
|
|
|
|
|
| ... | ... | @@ -1436,7 +1432,7 @@ by the appropriate choice of parameter `_C.conduction` in file |
|
|
|
Ohmic diffusion enters the induction equation and energy equation as a
|
|
|
|
field contribution given by
|
|
|
|
|
|
|
|
$\mathbf{E}_\mathrm{D}=\eta_\mathrm{D} \nabla\times\mathbf{B}$
|
|
|
|
$$\mathbf{E}_\mathrm{D}=\eta_\mathrm{D} \nabla\times\mathbf{B}$$
|
|
|
|
|
|
|
|
where $\eta_\mathrm{D}$ in units \[m$^2\cdot$s$^{-1}$\] is the diffusion
|
|
|
|
coefficient.
|
| ... | ... | @@ -1475,8 +1471,8 @@ user-defined ambipolar diffusion coefficient. |
|
|
|
Ambipolar diffusion enters the induction equation and energy equation as
|
|
|
|
a field contribution given by
|
|
|
|
|
|
|
|
$\mathbf{E}_\mathrm{AD}=\eta_\mathrm{AD}/\mu\mathbf{B}\times\left[(\nabla\times\mathbf{B})
|
|
|
|
\times\mathbf{B}\right]$
|
|
|
|
$$\mathbf{E}_\mathrm{AD}=\eta_\mathrm{AD}/\mu\mathbf{B}\times\left[(\nabla\times\mathbf{B})
|
|
|
|
\times\mathbf{B}\right]$$
|
|
|
|
|
|
|
|
where $\eta_\mathrm{AD}$ \[V$\cdot$m$\cdot$A$^{-1}\cdot$T$^{-2}$\]
|
|
|
|
denotes the ambipolar diffusion coefficient. The prefactor
|
| ... | ... | |