Finite Volumes with a Rusanov Riemann solver and explicit Euler time stepping, realised over a block-structured mesh. More...

Inheritance diagram for exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler:

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Collaboration diagram for exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler:

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Public Member Functions
	__init__ (self, Solver solver, int patch_size, int overlap=1, float cfl_constant=0.9, "toolbox.blockstructured.api.InterpolateHangingFaces.Scheme" interpolation=toolbox.blockstructured.api.InterpolateHangingFaces.Scheme.Linear, "toolbox.blockstructured.api.RestrictHangingFaces.Scheme" restriction=toolbox.blockstructured.api.RestrictHangingFaces.Scheme.Averaging, float min_volume_size=None, float max_volume_size=None)
	The constructor memorises the attributes.

str	kernel_function_name (self)
	Name of the generated time step kernel.

Solver.MeshAdaptation	create_default_mesh_adaptation (self)
	The Finite Volume schemes adapt the mesh and balance the load through exahype2.api.fv.AdaptMeshAndBalanceLoad by default.

	construct_output (self, exahype2_project, peano_project, time_step)
	Has to be implemented by subclass.

"toolbox.blockstructured.api.RestrictHangingFaces"	create_restriction_of_hanging_faces (self)
	Action set which restricts the projected fine data from the hanging faces onto the coarse faces.

Data Fields
	min_volume_size

	max_volume_size

	interpolation

	restriction

	patch_size
	Reduce the cells' maximum eigenvalues into the next time step size.

	overlap

	kernel_namespace

	cfl_constant
	Reduce the cells' maximum eigenvalues into the next time step size.

Protected Attributes
	_solver
	Build the reconstruction tasks befilling the patch_with_halo, which is logically temporary.

Protected Attributes inherited from exahype2.api.Solver.Solver.NumericalScheme
	_solver

Private Member Functions
	__create_data_structures (self)
	Create the mesh data structures (a Finite Volume patch per cell, plus the face-based overlap patches used to reconstruct its halo) this numerical scheme requires.

	__add_data_to_repository (self, peano_project)
	Consult Introduce a new numerical scheme for some information how this routine fits to the typical workflow when we introduce a new solver.

	__create_time_step_functions (self, output_directory)
	Calling this function is delayed until all PDE term information is provided.

	__construct_kernel_call (self, Target target, bool stateless)
	This function constructs the calls to the compute kernels based on the application PDE terms and the version chosen.

Detailed Description

Finite Volumes with a Rusanov Riemann solver and explicit Euler time stepping, realised over a block-structured mesh.

Definition at line 176 of file RusanovWithExplicitEuler.py.

Constructor & Destructor Documentation

◆ init()

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__init__	(		self,
		Solver	solver,
		int	patch_size,
		int	overlap = `1`,
		float	cfl_constant = `0.9`,
		"toolbox.blockstructured.api.InterpolateHangingFaces.Scheme"	interpolation = `toolbox.blockstructured.api.InterpolateHangingFaces.Scheme.Linear`,
		"toolbox.blockstructured.api.RestrictHangingFaces.Scheme"	restriction = `toolbox.blockstructured.api.RestrictHangingFaces.Scheme.Averaging`,
		float	min_volume_size = `None`,
		float	max_volume_size = `None`
	)

The constructor memorises the attributes.

However, it does not do this within this class, but it adds the important properties straight to the solver, so anybody else working against this solver knows about the properties introduced by the numerical scheme.

See also: __create_data_structures()

patch_size: int Number of Finite Volumes per axis within one patch (i.e. within one mesh cell).

overlap: int Number of Finite Volumes the halo layer reconstructed around a patch - from the neighbouring patches' faces - is wide.

cfl_constant: float Safety factor the admissible time step size (

See also: exahype2.api.fv.actionsets.ComputeGlobalCFLCondition, which this is passed straight through to) is scaled down by, relative to the theoretical CFL=1 stability limit h / (Dimensions * lambda_max). 0.9 is a conservative default for an explicit-Euler Finite Volume scheme; this codebase has no prior precedent value to match (grep for "cfl" outside this class finds only exaparty's unrelated SPH solvers, which default to 0.1).

interpolation: toolbox.blockstructured.api.InterpolateHangingFaces.Scheme How the scheme initialises the halo of a fine patch next to a coarser patch on an adaptive mesh. Whenever the time step reconstructs the halo of a fine cell, it interpolates the data of the adjacent coarse face onto the fine cell's hanging face (toolbox.blockstructured.api.InterpolateHangingFaces). The default is linear interpolation.

restriction: toolbox.blockstructured.api.RestrictHangingFaces.Scheme How the scheme hands the data of fine patches over to an adjacent coarser patch. Whenever the fine cells project their data onto their faces, the scheme restricts the data of the hanging faces onto the coarse face (toolbox.blockstructured.api.RestrictHangingFaces). The default is averaging.

min_volume_size: float The time step asks for a refinement of a cell only if its volumes are at least of this size (exahype2.api.blockstructured.DynamicMeshRefinement). None (the default) does not bound the refinement.

max_volume_size: float The time step asks for an erase, i.e. coarsening, of a cell only if the volumes of the coarser cell would be strictly smaller than this size. None (the default) does not bound the coarsening.

On a regular mesh, there are no hanging faces, and the two schemes are never used. The fluxes along a face between a coarse and a fine patch are not corrected, i.e. the scheme is not exactly conservative on adaptive meshes.

Reimplemented from exahype2.api.Solver.Solver.NumericalScheme.

Definition at line 184 of file RusanovWithExplicitEuler.py.

References exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__init__().

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__init__().

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Member Function Documentation

◆ __add_data_to_repository()

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__add_data_to_repository	(	self,
		peano_project
	)

private

Consult Introduce a new numerical scheme for some information how this routine fits to the typical workflow when we introduce a new solver.

Definition at line 376 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output(), and exahype2.api.rkfd4.CentralDifferencesWithRungeKutta.CentralDifferencesWithRungeKutta.construct_output().

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◆ __construct_kernel_call()

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__construct_kernel_call	(		self,
		Target	target,
		bool	stateless
	)

private

This function constructs the calls to the compute kernels based on the application PDE terms and the version chosen.

Definition at line 693 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output(), and exahype2.api.rkfd4.CentralDifferencesWithRungeKutta.CentralDifferencesWithRungeKutta.construct_output().

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◆ __create_data_structures()

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__create_data_structures ( self )

private

Create the mesh data structures (a Finite Volume patch per cell, plus the face-based overlap patches used to reconstruct its halo) this numerical scheme requires.

Ported from the legacy exahype2.solvers.fv.FV.create_data_structures(): one peano4.api.datamodel.Patch of patch_size^d Finite Volumes per mesh cell (_patch), plus a halo-augmented copy of it (_patch_with_halo, (patch_size+2*overlap)^d,

See also: toolbox.blockstructured.api.ReconstructPatchWithHalo) and two overlap patches of width 2*overlap attached to the mesh faces:

_patch_overlap_current_time_step: the persistent halo data toolbox.blockstructured.api.ReconstructPatchWithHalo reads from to rebuild _patch_with_halo (
See also
construct_output(), which hands it _patch/_patch_overlap_current_time_step/_patch_with_halo directly rather than the whole solver).
_patch_overlap_update: the projection of the just-updated _patch accumulated by the current sweep (
See also
exahype2.api.fv.actionsets.ProjectPatchOntoFaces), rolled over into _patch_overlap_current_time_step by exahype2.api.fv.actionsets.RollOverUpdatedFace once the update is complete.
_max_eigenvalue: one double per cell, named after the solver followed by MaxEigenvalue (e.g. EulerFVSmoothMaxEigenvalue), which holds the maximum eigenvalue of the patch after its last update (
See also
exahype2.api.fv.actionsets.UpdateCell). exahype2.api.fv.actionsets.ComputeGlobalCFLCondition reduces these values into the next time step size. It is modelled via DaStGen2 as an array of cardinality one. The array is a peano4.api.dastgen2.Peano4SmartPointerDoubleArray, i.e. the value resides on the heap.
All five are assigned onto self._solver (the shared exahype2.api.Solver instance both this numerical scheme and its surrounding solver's Solver.GridConstruction/Solver.Plotter counterparts hold a reference to as self._solver), not onto self, since the remaining FV action sets that need them -
See also
exahype2.api.fv.actionsets.ApplyDirichletBoundaryConditions, exahype2.api.fv.actionsets.UpdateCell, exahype2.api.fv.actionsets.ComputeGlobalCFLCondition - are handed that shared solver and look the patches up as solver._patch / solver._patch_overlap_*.
Storage is hardwired to smart pointers (peano4.api.datamodel's PatchToDoubleArrayWithSmartPointer), matching the legacy default (Storage.SmartPointers for both cell and face data) - the legacy Storage enum's other two backends (CallStack, Heap) are not exposed here.

Two pieces of the legacy method are deliberately not ported yet:

The cell/face label creation (exahype2.grid.create_cell_label()/create_face_label()) - that module has not been ported to the new API.
The load/store/compute guards (FV._provide_cell_data_to_compute_kernels_default_guard() and friends) - they are keyed off the legacy SolverState state machine, which the task-graph architecture has no equivalent of: a task only ever runs within its own phase's task graph in the first place, so "are we still constructing the grid" does not need to be re-checked at runtime the same way.

Definition at line 281 of file RusanovWithExplicitEuler.py.

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◆ __create_time_step_functions()

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__create_time_step_functions	(	self,
		output_directory
	)

private

Calling this function is delayed until all PDE term information is provided.

In this way we can avoid generating code that will not be used. The following information is required to translate a Python function using DSLHyPE:

template_parameters: the variables that are used within the Python function to represent external information
functor_parameters: the PDE terms that can be used by the solver
function: the Python function itself

TODO: Currently the MLIR types are passed manually here, this should ideally be inferred

Definition at line 629 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output(), and exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output().

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◆ construct_output()

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output	(	self,
		exahype2_project,
		peano_project,
		time_step
	)

Has to be implemented by subclass.

time_step: peano4.api.taskgraph.Graph The task graph of the surrounding exahype2_project's time stepping phase, so the numerical scheme can add its own tasks into it.

Reimplemented from exahype2.api.Solver.Solver.NumericalScheme.

Reimplemented in manipulate-solver-steps-illustrations.RusanovWithPostprocessing, and 20_additional-solver-steps.RusanovWithDensityFloor.

Definition at line 451 of file RusanovWithExplicitEuler.py.

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◆ create_default_mesh_adaptation()

Solver.MeshAdaptation exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.create_default_mesh_adaptation ( self )

The Finite Volume schemes adapt the mesh and balance the load through exahype2.api.fv.AdaptMeshAndBalanceLoad by default.

Reimplemented from exahype2.api.Solver.Solver.NumericalScheme.

Definition at line 440 of file RusanovWithExplicitEuler.py.

◆ create_restriction_of_hanging_faces()

"toolbox.blockstructured.api.RestrictHangingFaces" exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.create_restriction_of_hanging_faces ( self )

Action set which restricts the projected fine data from the hanging faces onto the coarse faces.

Every task which projects the solution onto the faces has to host this action set, so the faces between coarse and fine patches hold consistent data afterwards. Besides the time step, this is the projection at the end of the setup (exahype2.api.fv.SetupSimulationOverRegularGrid). The task has to write all of _patch_overlap_update, as averaging clears it first.

Definition at line 608 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output().

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◆ kernel_function_name()

str exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.kernel_function_name ( self )

Name of the generated time step kernel.

It carries the solver name, as do the kernels/<SolverName>_rusanov*.h files holding it, so two solvers' kernels do not clash.

Definition at line 273 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.__construct_kernel_call(), exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__create_time_step_functions(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.__create_time_step_functions(), and exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output().

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Field Documentation

◆ _solver

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler._solver

protected

Build the reconstruction tasks befilling the patch_with_halo, which is logically temporary.

On adaptive meshes, restrict the fine data from the hanging faces onto the coarse faces, before the roll over copies them.

Next project the new data onto the faces.

Reduce the cells' maximum eigenvalues into the next time step size.

Set the ghost volumes along the domain boundary before the reconstruction reads them.

Sommerfeld boundary conditions read the old face data within the roll over, i.e. it has to survive the reconstruction

No task is added if all axes are periodic or for Sommerfeld boundary conditions, which advance the ghost volumes within the roll over

Do the actual time step update

Runs in parallel to the projection onto the faces

Also roll over the solution

Sommerfeld boundary conditions advance the ghost volumes within the roll over (exahype2.api.blockstructured.BoundaryConditions)

Definition at line 449 of file RusanovWithExplicitEuler.py.

◆ cfl_constant

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.cfl_constant

Reduce the cells' maximum eigenvalues into the next time step size.

Runs in parallel to the projection onto the faces

Definition at line 269 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output(), and exahype2.api.rkfd4.actionsets.ComputeTimeStepSize.ComputeTimeStepSize.is_adaptive().

◆ interpolation

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.interpolation

Definition at line 262 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output().

◆ kernel_namespace

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.kernel_namespace

Definition at line 268 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__create_time_step_functions(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.__create_time_step_functions(), exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output(), and exahype2.api.rkfd4.CentralDifferencesWithRungeKutta.CentralDifferencesWithRungeKutta.construct_output().

◆ max_volume_size

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.max_volume_size

Definition at line 261 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output(), and exahype2.api.blockstructured.DynamicMeshRefinement.DynamicMeshRefinement.get_body_of_operation().

◆ min_volume_size

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.min_volume_size

Definition at line 260 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.SetupSimulationWithUserCodedRefinementCriterion.SetupSimulationWithUserCodedRefinementCriterion._create_adapt_mesh_task(), exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output(), and exahype2.api.blockstructured.DynamicMeshRefinement.DynamicMeshRefinement.get_body_of_operation().

◆ overlap

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.overlap

Definition at line 265 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__create_data_structures(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.__create_data_structures(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output(), and exahype2.api.fv.actionsets.InsertPatchInterior.InsertPatchInterior.get_body_of_operation().

◆ patch_size

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.patch_size

Reduce the cells' maximum eigenvalues into the next time step size.

Runs in parallel to the projection onto the faces

Definition at line 264 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.__create_data_structures(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.__create_data_structures(), exahype2.api.rkfd4.CentralDifferencesWithRungeKutta.CentralDifferencesWithRungeKutta.__create_data_structures(), exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.construct_output(), exahype2.api.fv.RusanovWithOptimisticExplicitEuler.RusanovWithOptimisticExplicitEuler.construct_output(), exahype2.api.blockstructured.DynamicMeshRefinement.DynamicMeshRefinement.get_body_of_operation(), and exahype2.api.fv.actionsets.InsertPatchInterior.InsertPatchInterior.get_body_of_operation().

◆ restriction

exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.restriction

Definition at line 263 of file RusanovWithExplicitEuler.py.

Referenced by exahype2.api.fv.RusanovWithExplicitEuler.RusanovWithExplicitEuler.create_restriction_of_hanging_faces(), and exahype2.api.rkfd4.CentralDifferencesWithRungeKutta.CentralDifferencesWithRungeKutta.create_restriction_of_hanging_faces().

The documentation for this class was generated from the following file:

src/exahype2/api/fv/RusanovWithExplicitEuler.py

Public Member Functions

Data Fields

Protected Attributes

Private Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ __init__()

Member Function Documentation

◆ __add_data_to_repository()

◆ __construct_kernel_call()

◆ __create_data_structures()

◆ __create_time_step_functions()

◆ construct_output()

◆ create_default_mesh_adaptation()

◆ create_restriction_of_hanging_faces()

◆ kernel_function_name()

Field Documentation

◆ _solver

◆ cfl_constant

◆ interpolation

◆ kernel_namespace

◆ max_volume_size

◆ min_volume_size

◆ overlap

◆ patch_size

◆ restriction

◆ init()