Users Guide for Clawpack inside AMROC |
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Up to now, this users guide is only a brief description how to use Clawpack inside AMROC. If other
discretization might be available in the future this document will have to be extended.
Setting up a new simulation
A new AMR computation has to be assembled out of several pieces of code. For the standard cases
this is quite simple, because already existing objects simply have to be linked together with
a few application specific functions.
A specific format of the Makefile
is required:
- $(EQUATION) selects the particular equations to be solved.
- $(EXECUTABLE) is the name of the executable.
- $(OBJS) Specifies application specific Fortran functions. See below.
Problem.h defines
the C++-Objects. In standard cases nothing has to be changed!
Application specific Fortran functions:
| init.f | Initial conditions.
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| physbd.f | Boundary conditions.
Predefined standard functions are in bc
and $(EQUATION)/rp.
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| combl.f | Initialize application
specific common blocks or create specific data files.
This function should write a file chem.dat with physical properties for hdf2v3 and hdf2file.
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| $(EQUATION)/rp/rpn.f | Equations specific Riemann solvers in
normal direction.
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| $(EQUATION)/rp/rpt.f | Equations specific Riemann solvers in
transverse direction. Not necessary in the one-dimensional case.
If dimensional splitting is applied by setting method(3) < 0
dummy-routines/rpt.f can be used.
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$(EQUATION)/rp/flx.f
$(EQUATION)/rp/rec.f |
These function have to be linked, if slope-limiting is applied by selecting method(2) = 3/4.
Otherwise dummy-routines/flx.f and dummy-routines/rec.f may be used.
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| $(EQUATION)/rp/chk.f | Physical consistency check for debugging.
If always method(4)=0 will be selected dummy-routines/chk.f may be used.
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| src.f | Source term for a splitting method. If
method(5)=0 dummy-routines/src.f can be linked.
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| setaux.f | Set data in an additional aux arrays.
method(7)=n sets the number of aux arrays. If no auxiliary data are used (method(7)=0)
link with dummy-routines/saux.f.
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Parameters in solver.in
Possible parameters and default values (in brackets []):
The order of the values in SolverControl{} should not be changed, to ensure that solver.in
can also be read by the visualizers hdf2v3 and hdf2file.
SolverControl {
| Restart[0] | = 0 No restart.
= 1 Restart the computation from the last checkpointed state. |
| Cells(1/2/3)[2] | Cell size of entire coarsest grid. Set the cells
size of unused dimensions to 1! The visualizers hdf2v3 and hdf2file, which are
written for general 3d problems read the solver.in-file, too. The number of cells in
each direction should always be dividable by GuCFactor (2 by default). |
GeomMin(1/2/3)[0.0]
GeomMax(1/2/3)[1.0] | Geometric dimensions of
the entire grid. Set GeomMin and GeomMax to 0.0 for unused dimensions to be compatible with
hdf2v3 and hdf2file. |
| PeriodicBoundary(1/2/3)[0] | = 0 No periodic boundary.
= 1 Periodic boundary conditions in particular direction. |
| CutOffs[0] | n < 11 Number of
regions that are cut out of the base grid. |
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| CCells(i,1/2,1/2/3) | Definition of the ith
cut out region. In each direction the index of the first and the last cell to be cut out should
be given. The number of cells of a cut out region in each direction should always be dividable
by GuCFactor (2 by default). |
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| MaxLevels[1] | = l Max. number of levels allowed.
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| RefineFactor(1...l)[2] | = Refinement factor used on a
particular level to create subgrids. |
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| Distribution[1] | = 1 DAGHCompositeDistribution
(Hilbert's space filling curve).
The following values select a fixed distribution of the coarsest grid. Higher levels
are not considered.
= 2 DAGHBlockXDistribution
= 3 DAGHBlockYDistribution
= 4 DAGHBlockZDistribution
= 5 DAGHBlockXYDistribution
= 6 DAGHBlockYZDistribution
= 7 DAGHBlockXZDistribution
= 8 DAGHBlockAllDistribution |
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| GuCFactor[1] | >= 1 Important especially for
DAGHCompositeDistribution. Coarsening factor on coarsest level for grid units
that are the basis for the distribution algorithm. E.g. the usage of the shadow
hierarchy for error estimation requires GuCFactor>=2. GuCFactor should always be
a power of 2! |
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| RedistributeEvery[0] | = 0 Redistribute the
hierarchy always.
= n Redistribute the hierarchy only after n coarse level steps. |
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| CheckEvery[0] | = n Write checkpointing files
after n coarse level time steps. Use 0 to suppress writting checkpointing files completely.
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| CheckpointName | = Name of checkpointing files. |
| OutputName(1..components) | = Basic file name for
each component that is written out.
Use - as a name to suppress a
particular component. |
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| StepControls[1] | n<11 Number of time step
controls that follow. |
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(1..n)-Time {
| Outputs[0] | = n HDF-outputs. Files are written exactly at
times LastTime/n. |
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| StepMode[0] | = 0 Use fixed TimeStep [0.01] until
LastTime [0.0] is reached.
= 1 Variable time steps on basis of CFLControl [0.8] until
LastTime is reached. Start with TimeStep as first step. TimeStepMax [0.0] is the maximal
time step possible.
= 2 Same as 1. Reject a step if CFL-No. is greater that CFLRestart [0.9]. |
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}
}
AMRSolver {
| MinEfficiency[0.7] | < 1.0 Efficiency of the cluster algorithm.
Minimal portion of cells flagged for refinement in a subgrid. |
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| BlockWidth[1] | = n Minimal size in
all directions of new subgrids. |
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| BufferWidth[2] | = n Buffer size around
flagged cells. Minimal value is 1. 2 is the ideal value. |
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| NestingBuffer[1] | = n Minimal buffer
size around subgrids. Conservative correction requires a minimal buffer size of 1. |
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| DoFixup[1] | = 1 Apply conservative
correction at coarse-fine interfaces. Should always be turned on.
= 0 No conservative correction. |
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| RegridEvery[1] | = 1 Always set flags and
recompose the hierarchy when necessary.
= 0 No recomposition of the hierarchy. Especially for testing. |
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ClawpackIntegrator {
| Method(2) | = 1 if only first
order increment waves are to be used.
= 2 if second order correction terms are to be added, with a
flux-limiter as specified by mthlim.
= 3 ==> Slope-limiting of the conserved variables, with a
slope-limiter as specified by mthlim(1).
> 3 ==> User defined slope-limiter method.
Slope-limiting is intended to be used with dimensional splitting!
If slope-limiting is applied $(EQUATION)/rp/flx.f and $(EQUATION)/rp/rec.f have
to be linked. Otherwise dummy-routines/flx.f and dummy-routines/rec.f may be used.
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1D case
2D case
| Method(3) |
= -1 Gives dimensional splitting using Godunov
splitting, i.e. formally first order accurate.
On a single computational nodes =-1 and =-2
will give identical results, but =-1 will be faster.
= -2 Dimensional splitting using Godunov splitting with
boundary update after each directional step.
The necessary ghost cell synchronization is done by
the surrounding AMROC framework.
This selection ensures that the solution of the
splitting method is independent of the number of
computational nodes.
If dimensional splitting is applied dummy-routines/rpt.f can be used.
= 0 Gives the Donor cell method. No transverse
propagation of neither the increment wave nor the correction wave.
= 1 if transverse propagation of increment waves
(but not correction waves, if any) is to be applied.
= 2 if transverse propagation of correction waves is also
to be included. |
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| Method(3) |
= -1 Gives dimensional splitting using Godunov
splitting, i.e. formally first order accurate.
On a single computational nodes =-1 and =-2
will give identical results, but =-1 will be faster.
= -2 Dimensional splitting using Godunov splitting with
boundary update after each directional step.
The necessary ghost cell synchronization is done by
the surrounding AMROC framework.
This selection ensures that the solution of the
splitting method is independent of the number of
computational nodes.
If dimensional splitting is applied dummy-routines/rpt.f can be used.
= 0 Gives the Donor cell method. No transverse
propagation of neither the increment wave
nor the correction wave.
= 10 Transverse propagation of the increment wave
as in 2D. Note that method (2,10) is
unconditionally unstable.
= 11 Corner transport upwind of the increment
wave. Note that method (2,11) also is
unconditionally unstable.
= 20 Both the increment wave and the correction
wave propagate as in the 2D case. Only to
be used with method(2) = 2.
= 21 Corner transport upwind of the increment wave,
and the correction wave propagates as in 2D.
Only to be used with method(2) = 2.
= 22 3D propagation of both the increment wave and
the correction wave. Only to be used with
method(2) = 2.
Recommended settings: First order schemes:
(1,10) Stable for CFL < 1/2
(1,11) Stable for CFL < 1
Second order schemes:
(2,20) Stable for CFL < 1/2
(2,22) Stable for CFL < 1
WARNING! The schemes (2,10), (2,11) are unconditionally unstable. |
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| Method(4)[0] |
Determines if an auxiliary function checks the physical consistency of the data in a subgrid.
= 0 No consistency check. In this case dummy-routines/chk.f can be used.
Otherwise $(EQUATION)/rp/chk.f should be linked.
= 1 Consistency check before computation of a subgrid.
= 11 Like 1. But program is aborted immediately if check fails. |
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| Method(5)[0] | Source term if splitting is used.
= 0 No source term. In this case dummy-routines/srcxx.f can be used.
= 1 Godunov splitting.
= 2 Strang splitting. |
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| Method(6)[0] | Use capa differencing.
Never used. |
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| Method(7)[0] | = n Number of components
in additional auxillary array.
If n=0 dummy-routines/saux.f can be used
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| Limiter(1...waves)[0] | = 1 Minmod
= 2 Superbee
= 3 van Leer
= 4 Monotinized centered
= 5 van Albada | |
}
AMRFlagging {
| TolGrad(1...components)[0.0] | = Limit
for scaled gradient |y(comp,i+1)-y(comp,i)| for a particular component |
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| TolErrEst(1..components)[0.0] | = Limit
for absolute error from Richardson extrapolation for a particular component. If TolErrEst=0.0 for all
components no error estimation is calculated. |
|
Other flagging criteria (e.g. for derived quantities or relative
errors) are available, if Problem.h uses an extended object for flagging.
}
}
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last update:
6/1/04
Blockstructured Adaptive Mesh Refinement in object-oriented C++
