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54 lines
2.0 KiB
Plaintext
54 lines
2.0 KiB
Plaintext
"CFDEMproject WWW Site"_lws - "CFDEM Commands"_lc :c
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:link(lws,http://www.cfdem.com)
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:link(lc,CFDEMcoupling_Manual.html#comm)
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:line
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voidfractionModel_dividedVoidFraction command :h3
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[Syntax:]
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Defined in couplingProperties dictionary.
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voidfractionModel divided;
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dividedProps
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\{
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alphaMin number1;
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interpolation;
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weight number2;
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porosity number3;
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\} :pre
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{number1} = minimum limit for voidfraction :ulb,l
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{interpolation} = flag to interpolate voidfraction to particle positions (normally off) :l
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{number2} = (optional) scaling of the particle volume to account for porosity or agglomerations. :l
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{number3} = (optional) diameter of the particle's representation is artificially increased according to {number2} * Vparticle, volume remains unaltered! :l
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:ule
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[Examples:]
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voidfractionModel divided;
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dividedProps
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\{
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alphaMin 0.2;
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\} :pre
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[Description:]
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The divided voidFraction model is supposed to be used when a particle (or its representation) is in the size range of a CFD cell. Satellite points are used to divide the particle's volume to the touched cells.
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The region of influence of a particle can be increased artificially by "porosity", which blows up the particles, but keeps their volume (for voidfraction calculation) constant.
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The particle volume occupied in the CFD domain can be adjusted by the parameter "weight", using Vparticle=dsphere^3*pi/6*weight.
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In the basic implementation of solvers, the void fraction is calculated based on all particles. Depending on the solver used, the void fraction calculation is also performed for a certain type of particles.
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The void fraction calculation is based on a three-step approach (reset, set and interpolate), i.e., the void fraction is time interpolated from a previous and a next void fraction field. Appropriate names for these fields have to be specified in the sub-dictionaries voidFracFieldNamesPrev and voidFracFieldNamesNext in the couplingProperties dictionary.
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[Restrictions:] none.
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[Related commands:]
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"voidfractionModel"_voidfractionModel.html
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