Bidirectionally Coupled Ray Tracing

Bidirectionally Coupled Ray Tracing

The Bidirectionally Coupled Particle Tracing study step is a special case of the Ray Tracing study step that is used to model bidirectionally coupled particle-field or fluid-particle interactions. It is available with the Ray Optics Module. It is similar to the Ray Tracing study step but has an additional section called Iterations, which determines the behavior of the iterative solver loop for self-consistently modeling ray-field interactions in the default solver sequence.

model.study(stdname).create(fname, "BidirectionallyCoupledRayTracing");

model.study(stdname).feature(fname).set(pname,value);

The following properties are available.

Table 6-96: Properties for Study Settings
Property	Value	Default	Description
charvel	String	c_const or 343 m/s	Group velocity used to convert path lengths to solution times when timestepspec=specifylength.
llist	Numeric vector		List of path lengths when timestepspec=specifylength.
lunit	String	m	Length unit when timestepspec=specifylength.
numberofreflections	Positive integer	5	Maximum number of reflections per ray for automatic stop conditions when raystopcond=reflections.
raystopcond	nostop \| noactive \| rayintensity \| reflections	nostop	Automatic stop condition in the default solver sequence.
rtol	Positive scalar	0.01	Relative tolerance, if usertol is on.
thresholdintensity	String	1[W/m^2]	Threshold intensity for automatic stop conditions when raystopcond=rayintensity.
timestepspec	specifytime \| specifylength	specifytime	Determines whether the time intervals are entered directly or in terms of a path length.
tlist	Numeric vector		Time list when timestepspec=specifytime.
tunit	String	ns or ms	Time unit when timestepspec=specifytime.
usertol	on \| off	off	Physics-controlled or user-defined tolerance.

Table 6-97: Properties for Plot Results While Solving
Property	Value	Default	Description
plot	on \| off	off	Plot while solving.
plotgroup	String	default	Plot group to use for plot while solving.
probefreq	pout \| psteps	pout	Where to update probes.
probes	Vector of strings		Probes to use when probesel=manual.
probesel	all \| none \| manual	all	Probes to compute.
plotfreq	tout \| tsteps	tout	Where to update plot.

Table 6-98: Properties for Physics and Variables Selection
Property	Value	Default	Description
activate	Vector of strings		Choose physics interfaces to solve for. The length of the vector is two times the number of physics interfaces. For example, with two physics interfaces, g and c: new String[]{"g", "on", "c", "off"}.
disabledcoupling	Vector of strings		Disabled coupling features
disabledphysics	Vector of strings		Disabled physics interfaces.
disabledvariables	Vector of strings		Disabled variables.
discretization	Vector of strings		Select discretizations for physics interfaces. The length of the vector is two times the number of physics interfaces. For example, with two physics interfaces, g and c: new String[]{"g", "disc1", "c", "disc2"}.
useadvanceddisable	on \| off	off	Modify physics tree and variables for study step.

Table 6-99: Properties for Iterations Section
Property	Value	Default	Description
expr	String	1	Global expression used to compute relative error when method=convergence.
iter	Positive integer	5	Number of iterations of the solver loop when method=iterations.
maxiter	Positive integer	25	Maximum number of iterations in the solver loop when method=convergence.
method	convergence \| iterations	iterations	Choose whether termination of the solver loop is based on the convergence of a global variable or a fixed number of iterations.
miniter	Positive integer	1	Minimum number of iterations in the solver loop when method=convergence.
rtolterm	Positive real number	0.001	Relative tolerance for termination of the solver loop when method=convergence.
rtolthresh	Positive real number	1	Threshold used to avoid division by zero while computing the relative error when method=convergence.

Table 6-100: Properties for Values of Dependent Variables
Property	Value	Default	Description
initmethod	init \| sol	init	Method for initial values for variables solved for.
initstudy	String		Reference to study or "zero" for zero solution.
manualsolnum	Vector of integers	[1]	Index to solution for initial value for variables solved for.
notlistsolnum	Vector of integers	[1]	Indices to selected solutions for values for variables not solved for.
notmanualsolnum	Vector of integers	[1]	Indices to solutions for values for variables not solved for.
notsolmethod	init \| sol	init