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CFDEMcoupling-PFM/doc/CFDEMcoupling_dicts.txt
2018-07-26 13:04:30 +02:00

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"CFDEMproject Website"_lws - "Main Page"_main :c
:link(lws,http://www.cfdem.com)
:link(main,CFDEMcoupling_Manual.html)
:line
4. Dictionaries :link(1_4),h3
4.1 couplingProperties dictionary :link(couplingProperties),h4
[General:]
In the {couplingProperties} dictionary the setup of the coupling routines of the
CFD-DEM simulation are defined.
[Location:] $caseDir/CFD/constant
[Structure:]
The dictionary is divided into two parts, "sub-models & settings" and "sub-model
properties".
In "sub-models & settings" the following routines must be specified:
modelType :ulb,l
couplingInterval :l
voidFractionModel :l
locateModel :l
meshMotionModel :l
regionModel :l
IOModel :l
dataExchangeModel :l
averagingModel :l
forceModels :l
momCoupleModels :l
turbulenceModelType :l
:ule
In "sub-model properties" sub-dictionaries might be defined to specify model
specific parameters.
[Settings:]
Reasonable example settings for the {couplingProperties} dictionary are given in
the tutorial cases.
modelType :pre
{modelType} refers to the formulation of the equations to be solved. Choose "A",
"B" or "Bfull", according to "Zhou et al. (2010)"_#Zhou2010. Model "A" requires
the use of the force models gradPForce and viscForce, whereas "B" requires the
force model "Archimedes". "Bfull" refers to model type I.
couplingInterval :pre
The coupling interval determines the time passing between two CFD-DEM data
exchanges.
A useful procedure would be:
Set the DEM time step in the LIGGGHTS input file according to the needs of the
pure DEM problem. :olb,l
Set the {couplingInterval}, which refers to the DEM time steps. Depending on the
problem you will need to have a close (small couplingInterval) or loose
coupling. :l
Choose the CFD time step in the controlDict. It must be equal to or smaller than
the coupling time, otherwise you will get the error: "Error - TS bigger than
coupling interval!". :l,ole
[Example:]
Choosing DEMts=0.00001s and couplingInterval=10 means that an exchange of data
(=coupling) will happen every 0.0001s.
:line
4.2 liggghtsCommands dictionary :link(liggghtsCommands),h4
[General:]
In the {liggghtsCommands} dictionary LIGGGHTS commands which are to be executed
during a coupled CFD-DEM simulation are specified.
[Location:] $caseDir/CFD/constant
[Structure:]
The dictionary is divided into two parts, first a list of
"liggghtsCommandModels"_CFDEMcoupling_models.html#lcm is defined, then the
settings for each model must be specified.
[Settings:]
Reasonable example settings for the {liggghtsCommands} dictionary are given in
the tutorial cases.
:line
:link(Zhou2010)
[(Zhou, 2010)]
"Discrete particle simulation of particle-fluid flow: model formulations and their applicability",
Zhou, Z. Y., Kuang, S. B., Chu, K. W. and Yu, A. B., J. Fluid Mech., 661, pp. 482-510 (2010)