snek5000.solvers.base#

Nek5000 base solver#

A bare Nek5000 solver which does not rely on any user parameters.

Classes

Simul

alias of SimulNek

SimulNek(params)

Simulation class
class snek5000.solvers.base.SimulNek(params)[source]#

Simulation class

Parameters

  • params (Parameters) – Input parameters for the simulation run.

  • write_files (bool, optional) – Write simulation files, including usr, box, SIZE files. By default all files are written.

Examples

>>> from snek5000.solvers.base import Simul
>>> params = Simul.create_default_params()
>>> sim = Simul(params)

Notes

Here, only the documention for params.nek is displayed. For the documentation on params.oper see snek5000.operators.

Documentation for params.nek

The parameters in params.nek are used by Snek to produce the Nek file .par, which is documented here Parameter File (.par).

Note

For these parameters, there is nearly a direct correspondance between Nek5000 par file keys and Snek5000 parameter variable names, with only camelCase <-> snake_case conversions. This is implemented in snek5000.params.

The sections are:

  • general (mandatory)

  • problemtype

  • mesh

  • velocity

  • pressure (required for velocity)

  • temperature

  • scalar%%

  • cvode

When scalars are used, the keys of each scalar are defined under the section scalar%% varying between scalar01 and scalar99.

There is a mechanism to enable/disable these sections so that they are used or not to produce the .par file (see our tutorial on writting new solvers).

Documentation for params.nek.general

See table GENERAL keys in the .par file

[GENERAL]
startFrom =
stopAt = numSteps
endTime = <real>
numSteps = 1
dt = <real>
variableDt = yes
targetCfl = 0.5
writeControl = timeStep
writeInterval = 10
filtering = none
filterModes = 2
filterCutoffRatio = 0.65
filterWeight = 12.0
writeDoublePrecision = yes
dealiasing = yes
timeStepper = BDF2
extrapolation = standard
optLevel = 2
logLevel = 2

Documentation for params.nek.problemtype

See table PROBLEMTYPE keys in the .par file

[PROBLEMTYPE]
equation = incompNS
variableProperties = no
stressFormulation = no

Documentation for params.nek.velocity

See table VELOCITY keys in the .par file

[VELOCITY]
residualTol = <real>
residualProj = no
writeToFieldFile = yes
viscosity = <real>
density = <real>

Documentation for params.nek.pressure

See table PRESSURE keys in the .par file

[PRESSURE]
residualTol = <real>
residualProj = no
writeToFieldFile = yes
preconditioner = semg_xxt

Documentation for params.nek.mesh

See table MESH keys in the .par file

[MESH]
writeToFieldFile = yes

Documentation for params.nek.temperature

See table TEMPERATURE keys in the .par file

[TEMPERATURE]
residualTol = <real>
residualProj = no
writeToFieldFile = yes
solver = helm
advection = yes
absoluteTol = <real>
conjugateHeatTransfer = no
conductivity = <real>
rhoCp = <real>

Documentation for params.nek.scalar01

See table SCALAR%% keys in the .par file

[SCALAR01]
residualTol = <real>
residualProj = no
writeToFieldFile = yes
solver = helm
advection = yes
absoluteTol = <real>
density = <real>
diffusivity = <real>

Documentation for params.nek.cvode

See table CVODE keys in the .par file

[CVODE]
InfoSolver#

alias of InfoSolverNek

class Parameters(*args, **kwargs)#

Container for reading, modifying and writing par files.

Parameters

tag – A string representing name of case files (for example: provide "abl" for files like abl.usr, abl.par etc).

classmethod create_default_params()[source]#

Generate default parameters. params.nek contains runtime parameters consumed by Nek5000.

classmethod load_params_from_file(path_xml=None, path_par=None)[source]#

Instantiate a Parameters instance and populate it from params_simul.xml or case.par

Create a symlink towards the start_from file

snek5000.solvers.base.Simul#

alias of SimulNek