transparentBndry

transparentBndry

Works with VSimPD, and VSimMD licenses.

In this particle sink, a portion particles are transferred through with the remainder either reflected or absorbed at the boundaries. The fraction of particles that are either transferred or reflected through the boundary is based on the transparency parameter which is expected to be between 0 and 1.0. For every particle at the boundary, a random number is picked and compared with the given transparency parameter.

In absorb mode if the random number is below the transparency parameter, the particle is absorbed at the boundary. For example, if transparency = 0.10, 90% of particles are transmitted through the boundary. Absorb mode is enabled by setting the absTransparenPtclFlag parameter to True.

In reflect mode if the random number is above the transparency parameter, the particle is reflected at a user specified velocity. For example, if transparency = 0.90, 90% of particles are transmitted through the boundary. Reflect mode is enabled by setting the reflectPtcls parameter to True.

transparentBndry Parameters

minDim (integer)

Minimum dimensionality for which this sink is applicable (1, 2, or 3).

lowerBounds (integer vector)

Gives lower bounds of the particle sink in cell indices.

upperBounds (integer vector)

Gives upper bounds of the particle sink in cell indices.

direction (double vector)

The direction of the outward normal for the reflecting plane in the case that particle is reflected at the boundary.

surface (double, required)

The location of the reflecting plane in the case that particle is reflected at the boundary.

transparency (double, required)

The transparency parameter which is a value between 0 and 1.0. Particle at the boundary are transferred through the boundary or reflected at the boundary based on the transparency parameter and operating mode.

absTransparentPtclFlag (flag, optional, default = false)

A flag to enable absorb mode of the boundary. Cannot be set to true if reflectPtcls is also true.

reflectPtcls (flag, optional, default = false)

A flag to enable reflect mode of the boundary. Cannot be set to true if absTransparentPtclFlag is also true. If set the average and thermal velocities of the reflected particles are given by vbar and vsig respectively.

vbar (double vector)

Average velocity of the particles in the x, y, and z directions. Only applied to reflected particles.

vsig (double vector)

Positive value denoting the thermal velocity in the x, y, and z directions. Only applied to reflected particles.

transparentBndry Example Block

<ParticleSink rightXeIonAbsorber>
  kind = transparentBndry
  # Bounds specified with physical indexing
  lowerBounds = [ABS_LOC_LB -1 -1]
  upperBounds = [ABS_LOC_UB NY1 NZ1]
  direction = [-1.0 0.0 0.0]
  surface = $XMIDm1 + 0.25*DX$
  # this is the param that decides percentage transmitted, or absorbed
  transparency = 0.8
  # CANNOT HAVE absTransparentPtclFlag and reflectPtcls = true.
  # if true this will absorb percentage particles  = transparency
  # absTransparentPtclFlag = true
  # if true the percentage reflected particles = 1 - transparancey
  reflectPtcls = true
  # thermal velocity of the reflected particles (so only applies if reflectPtcls = true)
  vsig = [VTH_TRNS VTH_TRNS VTH_TRNS]
  # average velocity of the reflected particles (so only applies if reflectPtcls = true)
  vbar = [-1.e6 0.0 0.0]
</ParticleSink>