vertexJetUpdater (1d, 2d, 3d)¶

Initializes a fluid jet based on a tip location and the vector from a center point. Can be used to initialize multiple jets based on ideal gas laws or general equation of state using Propaceos tables. This updater was designed for simulating plasma jet merging experiments.

Data¶

out (string vector, required)
The nodalArray in which to store the initialized fluid jet variables. If multiple out nodalArray are specified, then each nodalArray must have the same number components; each out data structure will be initialized according to this updater.

Parameters¶

width (float)
The width of the initialization region. The jet is initialized in a region with width width which is perpendicular to the direction from the jet vertex to the origin.
length (float)
The length of the initialization region. The jet is initialized in a region from the vertex to a distance length from the tip of the vertex away from the origin.
model (string)
The equation system that should be used to model the jet. Model should be a fluid system such as eulerEqnEqn, idealMhdEqn, twoTemperatureMhdEqn, twoTemperatureMhdEosEqn. USim will request that values that need to be initialized in the individual models be initialized in this updater as well.
origin (float vector)
The location where the jet points.
radialVelocity (float)
Required only if the velocityFunction block is not specified. Provides a bulk velocity for the jet.
numberDensity (float)
Characteristic number density of the fluid. If the normalizedDensityFunction has a peak value of 1 then the peak value of the number density of the jet will be numberDensity. Required if speciesMass is specified. This term is also required if a propaceos filename is specified.
speciesMass (float)
Mass of the atomic species (in Kg). Required if numberDensity is specified. The parameter is also required if a propaceos filename is specified.
density (float)
If neither numberDensity or speciesMass is specified then USim expects the characteristic mass density density to be specified.
pressure (float)
The pressure of the jet (constant throughout the jet). Either the pressure or temperature for the jet must be defined. USim checks if the pressure is set first and if it is it uses that for initialization, otherwise it checks for temperature.
temperature (float)
The temperature of the jet. Either the pressure or the temperature for the jet must be defined. USim checks if the pressure is set first and if it is it uses that for initialization, otherwise it checks for temperature.
vertex_n (float vector)
vertex_n defines the tip of the nth jet. n must be a number from 0 to the number of jets in the simulation. If you skip a number the subsequent jets will be ignored. Each jet has the exact same properties, but different orientations. The jet points towards the origin.
xAxis (float vector)
Allows the user to define an alternative xAxis. The coordinates for the jet vertex will be rotated to the new axis. Magnitude of the vector does not matter.
yAxis (float vector)
If the user defines an xAxis they may also define a yAxis otherwise USim picks its own y Axis. The yAxis should be chosen perpendicular to the xAxis. The Magnitude of the vector does not matter.
filename (string)
Name of the propaceos file to use if a general equation of state is required.
includeElectronTemperature (boolean)
If filename is specified then you may or may not need to have the electron energy initialized by USim, depending on the model being used. A two-temperature model will need to set the electron energy along with the bulk energy.
electronTemperatureIndex (int)
If the includeElectronTemperature is true then the user will need to specify the index in the in vector for the electron energy equation so USim knows where to initialize the electron energy.

Sub-Blocks¶

normalizedDensityFunction (block)
The desired plasma jet density is scaled by the normalized density function. As a result the normalized density function should have values that range from 0 to 1. The density function is a function of x,y,z where x is measured from the tip of the jet along its axis. y and z are perpendicular to this direction.
velocityFunction (block)
The velocity function specifies the velocity of the jet as a function of space x,y,z. The density function is a function of x,y,z where x is measured from the tip of the jet along its axis. y and z are perpendicular to this direction.

Example¶

 <Updater jetSet>
kind = vertexJetUpdater3d

origin = [0.0, 0.0, 0.0]
width = 0.05
length = 0.5

radialVelocity = $-U$

numberDensity = $RHO_JET/MI$
speciesMass = MI
temperature = TKELVIN

<normalizedDensityFunction>
kind = exprFunc
preExprs = ["R=1.1e-2","zd=4.5e-2","r=sqrt(y*y+z*z)","alpha=3.8",\
"G=exp(-(r*r/(R*R)))","kappa=(x/(alpha*zd))^alpha"]
exprs = ["max(1.0*G*kappa*exp(alpha-(x/zd)),1.0e-6)"]
</normalizedDensityFunction>

vertex0 = [0.25, 0.0, 0.0]
vertex1 = [0.0, 0.25, 0.0]
vertex2 = [0.0, 0.0, 0.25]

model = idealMhdEosEqn
mu0 = MU0

onGrid = domain
filename = Ar_Ni_1e^10_10group_NLTE_20110427.prp

out = [q]
</Updater>