GfsDropletToParticle

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-This is an attempt to decode how the GfsDropletToParticle works basing on the attempt to [[GfsParticleList]]. Please feel free to edit this page and correct me too. +[[GfsDropletToParticle]] in GModule [[particulates]] converts small detached regions of positive [[GfsVariable]] (usually a [[GfsVariableTracerVOF]], so that the regions correspond to "droplets") into discrete point-particles with their own equations of motion, adding them to a [[GfsParticleList]].
-[[GfsDropletToParticle]] is a [[GfsParticleList]]. "Droplet" can be removed from the flow field and converted to particle which will be tracked with Lagrangian method.+The syntax in parameter files is:
-<pre> GfsDropletToParticle { start = 1 istep = 1 } GfsParticulate { Id X Y Z MASS VOLUME Vx Vy Vz Fx Fy Fz } { GfsForceLift Cl GfsForceDrag Cd GfsForceBuoy } T { min = 20 reset = 0. density=1. } </pre> + [ [[GfsParticleList]] ] T { min = 20 reset = 0. density = 1. }
-The first bracket is used to set the starting time, time-step ... associated with particle motion.+
-[[GfsParticulate]] is the type of Lagrangian particle that is used. The following bracket is the list of Lagrangian particles. Each line for one particle. See [[GfsParticle]] or [[GfsParticulate]] for more details. This bracket can be empty since [[GfsDropletToParticle]] will convert droplet to particle and list the information in the bracket.+Note that the bracket following the type of particle ([[GfsParticle]] or [[GfsParticulate]]) in the [[GfsParticleList]] syntax can be empty here since it is [[GfsDropletToParticle]] itself that will populate the list dynamically.
-The third bracket is where the forces acting on the Lagrangian particles. See [[GfsForceDrag]], [[GfsForceLift]] and [[GfsForceBuoy]] for details.+The <code>T</code> is a variable for tagging the droplet. Usually, <code>T</code> is a [[GfsVariableTracerVOF]].
-The "T" is a variable for tagging the droplet. Usually, "T" is a [[GfsVariableTracerVOF]].+The last bracket contains the conversion parameters. A region of the tracer variable smaller than <code>min</code> cells will be <code>reset</code> to the specified value and converted to a particle with the specified <code>density</code>.
- +
-The last bracket contains the convertion parameters. Droplet smaller than "min" cells will be converted to a particle with density of "density" and the variable of the cells which the droplet location occupied will be set to "reset".+
* [[GfsEvent]] * [[GfsEvent]]

Revision as of 15:17, 1 August 2012

GfsDropletToParticle in GModule particulates converts small detached regions of positive GfsVariable (usually a GfsVariableTracerVOF, so that the regions correspond to "droplets") into discrete point-particles with their own equations of motion, adding them to a GfsParticleList.

The syntax in parameter files is:

 [ GfsParticleList ] T { min = 20 reset = 0. density = 1. }

Note that the bracket following the type of particle (GfsParticle or GfsParticulate) in the GfsParticleList syntax can be empty here since it is GfsDropletToParticle itself that will populate the list dynamically.

The T is a variable for tagging the droplet. Usually, T is a GfsVariableTracerVOF.

The last bracket contains the conversion parameters. A region of the tracer variable smaller than min cells will be reset to the specified value and converted to a particle with the specified density.

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