Particle

Create a massless particle tracing plot.

Syntax

model.result(<pgtag>).create(<ftag>,"Particle");

model.result(<pgtag>).feature(<ftag>).set(property, <value>);

model.result(<pgtag>).feature(<ftag>).run();

Description

model.result(<pgtag>).create(<ftag>,"Particle") creates a massless particle tracing plot feature named <ftag> belonging to the plot group <pgtag>.

With massless particle tracing, you can visualize path lines, that is, trajectories of particles released in a flow field, which can be time-dependent or static. For time-dependent flows you can also use a snapshot in time of the flow field as a static field. The motion of the particles does not affect the flow field. Particle tracing is available in 2D and 3D plot groups.

The following properties are available:

Table 7-60: Valid Property/Value Pairs for Particle Tracing Plots

Property	Value	Default	Description
arrowbase	heat|tail| center	head	Whether the head, tail, or center of the arrow is located at the particle position.
arrowexpr	string array		Active when pointtype is set to arrow. Determines the direction in which the arrow points.
arrowlength	logarithmic| normalized| proportional	proportional	The arrow scaling: Proportional uses the actual arrow length, normalized a unit length, and logarithmic a length proportional to the logarithm of the arrow length.
arrowscale	positive double	1	If arrowscalefactor is true: the length scale factor
arrowscaleactive	boolean	false	If true, arrowscale is used; otherwise the scale factor is computed automatically.
arrowtype	Arrow|cone	Arrow	The type of arrow to draw.
atol	manual | automatic	automatic	Whether to specify a manual absolute tolerance for the position. automatic indicates that the absolute tolerance for the position is the mean of the lengths of the bounding box of the geometry multiplied by the relative tolerance.
atolpos	positive double	0.001	Absolute tolerance for the position. Active when atol is set to manual.
bndcoord	double array	0	Vector of values from 0 to 1 to describe the start points. Active when bndmethod is set to coord. Available in 2D only.
bndmethod	number | coord	number	Active when posmethod is set to bnd. Available in 2D only.
bndnumber	positive integer	10	The number of equidistant start points along the selected boundaries. Available in 2D only.
bndselection	Reference to a named selection on boundaries	First available named selection	The boundaries to start from. Available in 2D only.
comettailexpr	String array		Active when pointtype is set to comettail. Determines the direction in which the comet tail points.
const	String array of property/value pairs	Empty	Parameters to use in the expressions.
customlinecolor	RGB-triplet	{1,0,0} or last used color.	The uniform color to use for lines. Active when linecolor is set to custom.
custompointcolor	RGB-triplet	{1,0,0} or last used color.	The uniform color to use for points. Active when pointcolor is set to custom.
data	none | parent | data set name	parent	The data set this feature refers to.
descr	String	Model-dependent	The description of the expressions in expr. Is used in the automatic title.
descriptionintitle	on | off	on	Whether the title contribution should contain the description when titletype is custom
dropfreq	positive double	1	Particles are released at these intervals when dropmethod is set to freq.
dropmethod	once | freq | times	once	Method to use when releasing particles.
droptimes	double array	1	The specific times when to release particles. Used when dropmethod is set to times.
edgetol	positive double	0.001	The absolute tolerance controlling how close to the geometry boundary the path lines are cut when they exit the geometry. A lower value cuts the line closer to the geometry boundary.
expr	String array of length 2 in 2D and 3 in 3D	Model-dependent	Expressions for the components to plot.
hmax	double	0.1	The maximum time step. Active when stepsize is set to manual.
hstart	double	0.1	The initial time step. Active when stepsize is set to manual.
inheritarrowscale	Boolean	true	If inheritplot is not none: Determines if the arrow scale is inherited.
inheritdeformscale	Boolean	true	If inheritplot is not none: Determines if the deformation scale is inherited.
inheritplot	none | plot name	none	The plot that sphere scale, tube scale, and deformation scale is inherited from.
inheritspherescale	Boolean	true	If inheritplot is not none: Determines if the sphere scale is inherited.
inherittubescale	Boolean	true	If inheritplot is not none and linetype is tube: Determines if the tube scale is inherited.
interp	double array	Time corresponding to last selected solnum for transient levels.	The time to use, for transient levels. Available when data is not parent and the underlying data is transient.
linecolor	custom | black | blue | cyan | green | magenta | red | white | yellow	black (2D), red (3D)	The uniform color to use for lines.
linetype	none | line | tube	line	Plot particle traces as lines or tubes, or not at all.
logrange	double > 1	100	If arrowlength is logarithmic: The ratio between the maximum arrow length and the arrow length below which no arrow is drawn.
looplevel	array of non-negative integers and strings	Last solution for transient or parametric solution for each level. Otherwise first solution for each level.	The index of the solution to use, per level, or interp, but only for transient solutions. Available when data is not parent and the underlying data has multiple solutions.
maxsteps	positive integer	1000	The maximum number of steps to use in the particle simulation. Active when maxstepsactive is set to on.
maxstepsactive	on | off	off	Whether to manually specify the maximum number of steps used in particle simulation. off indicates that the limit varies in this way: for static flow fields, the algorithm uses the value 1000; for time-dependent flows, there is no upper limit of the number of steps, and the particle simulation goes on until it reaches the end time.
outersolnum	non-negative integer	1	The index of the outer solutions to use. Applicable only for parametric sweep models.
pointcolor	custom | black | blue | cyan | green | magenta | red | white | yellow	red	The uniform color to use for points.
pointdom	disappear | stick	stick	stick plots the points on the boundary at the exit point, and disappear does not render these points at all.
pointlineanim	on | off	off	When animating particle tracing plots with points, this property indicates whether the points at the current time should appear on top of the lines.
pointautoscale	on | off	on	If enabled, the point radii are scaled so that the maximum radius is 0.01 of the plot scale.
pointradiusexpr	String	1	The point radius expression.
pointtype	none | point | comettail	none	Selects between plotting the path lines’ endpoints as points, comet tails, or not at all.
posmethod	start | bnd	start	The type of particle tracing positioning. Choose specific start points or a boundary to start from. Available in 2D only.
prefixintitle	String	Empty	Added prefix to contribution to title.
radiusexpr	String	1	The tube radius.
resolution	coarser | coarse | normal | fine | finer | extrafine		Affects the number of output points by adding points between each time step taken in the ODE solver, using a 4th-order interpolation, to produce a smoother output.
rtol	positive double	0.001	The relative error tolerance that the ODE solver uses.
solnum	non-negative integer	Last solution for transient or parametric solution. Otherwise first solution.	The index of the solution to use. Available when data is not parent and the underlying data has multiple solutions.
solrepresentation	solnum | solutioninfo	solutioninfo	Indicates which method of selecting solutions is active.
static	on | off	off	Only affects time-dependent problems. When set to on, this property freezes the time and considers this a static flow field.
statictend	double	1	The maximum time at which to end the particle-tracing simulation for static flow fields. Active when statictendactive is set to on.
statictendactive	on | off	off	Whether to specify the end time for static flow fields automatically. (For time-dependent flows, the automatic end time is the last time that the time-dependent solver returns.) When set to off, there is no upper limit of the time. In this case, the particle simulation goes on until all particles exit the geometry or the simulation reaches the maximum number of steps.
stepsize	automatic | manual	automatic	Whether to specify initial (hstart) and maximum (hmax) time step manually.
suffixintitle	String	Empty	Added suffix to contribution to title.
t	double	Time corresponding to last selected solnum.	The time to use, for transient problems. Available when data is not parent and the underlying data is transient.
tailscale	positive double	1	Active when pointtype is set to comettail and tailscaleactive is on. Specifies the manual scale factor with which the comet tail expression is multiplied.
tailscaleactive	on | off	off	Active when pointtype is set to comettail. Specifies whether manual tail scaling is enabled.
timeinterp	on | off	off	on if t is used to determine time steps, off if solnum is used.
title	String	The auto-title.	The title to use when titletype is manual
titletype	auto | custom | manual | none	auto	auto if the title contribution should be computed automatically, possibly using the group’s customization. custom if the title contribution should be computed automatically, but customized. manual if the manual title contribution should be used (the title property). none if no title contribution should be used.
tstart	double	0	Manual start time. Active when tstartactive is set to on.
tstartactive	on | off	off	on indicates a manual start time (set in the tstart property). Off indicates that the start time becomes either the first time value that the time-dependent solver returns or 0 for stationary flows. Available when dropmethod is set to once or freq.
tubeautoscale	on | off	on	If enabled, the tube radii are scaled so that the maximum tube radius is 0.02 of the plot scale.
tvar	String	partt	The name of the variable for time. Normally there is no need to change the default name. You can use this names in expressions as well as for the color when coloring the path lines according to an expression.
typeintitle	on | off	on	Whether the title contribution should contain the type when titletype is custom.
xcoord	double array	Empty	Absolute coordinates in the x-direction, active when posmethod is set to start.
ycoord	double array	Empty	Absolute coordinates in the y-direction, active when postmethod is set to start.
zcoord	double array	Empty	Absolute coordinates in the z-direction, active when posmethod is set to coord. Available in 3D only.

Attributes

Color (applies to lines), Deform

See Also

ParticleMass, Streamline