Boundaries

This dialog is opened via Settings Menu.

In the Boundaries dialog you can display and define boundary conditions for a set of variables that are to be solved (e.g. temperature) and for each line in the drawing.

Boundaries dialog 

Figure 27. Boundaries dialog

Item

Description

lines selected

Shows the number of selected lines. All settings are applied only to the selected lines.

hide

The boundary conditions are not shown in the drawing.

show

The boundary conditions are shown in the drawing for the variable selected.

show all

All boundary conditions are shown in the drawing for all variables.

Variable

Selects the variable for specifying the boundary conditions.

Type

Selects the type of boundary conditions for the selected variable and the selected line(s). Default is No boundary. Which boundary conditions are available depends on the variable selected.

For temperature, velocity U, velocity V, velocity W, pressure, stream function, concentration, in-phase potential and out-of-phase-potential the following boundaries are available. In the case of the azimuthal velocity , VelocityW, the value given specifies rounds per second. Conditions affecting axial and radial velocity components, like Marangoni, Normal Velocity, Tangential velocity, Zero velocity are set via VelocityU only.

  • Neumann

    Specifies a constant flux density of the variable normal to the line. e.g. you can specify an adiabatic boundary condition setting the flux = 0, or define a function f(l) along the line.

  • Dirichlet

    Specifies a fixed value of the variable along the line. You can set a constant value along the line, a function f(l) along the line or a profile.

  • Poincaré

    Specifies that the flux is proportional to the difference between the value of the variable on the line and a given reference value. The reference value can be specified along a chosen boundary line f(l). The coefficient can be specified as a function of the variable itself f(x).

  • Temperature dependent Dirichlet

    Specifies a fixed value of the variable along the line. The value used is, computed from the value of the temperature variable at the line (f(T)). The usage of profile files is not supported by this boundary type. This boundary type is not available for the variable temperature and in/out phase potential.

  • Temperature dependent Poincaré

    Specifies that the flux is proportional to the difference between the value of the variable on the line and a given reference value. The reference value can be specified as a function of the temperature at the given position f(T). The coefficient can also be specified as function of the temperature f(T). This boundary type is not available for the variable temperature and in/out phase potential. The usage of profile files is not supported by this boundary type.

    For details see Boundary Conditions.

For UVW velocities the following boundaries are available:

  • Zero velocity

  • Normal velocity

  • Tangential velocity

  • Marangoni

  • Outflow

Value

Input field for the value of the desired boundary type.

Profile

Clicking on this check box activates the input field for a file name containing a profile of boundary conditions ( *.pro file), which vary along the selected lines or are time-dependent.

File name

Specifies a *.pro file containing the desired boundary conditions.

Browse

Selects a *.pro file containing boundary conditions.

Tip

You do not need to enter the path, if the *.pro file is in the same directory as the *.crys file.

column

Specifies the column number of the boundary condition in the *.pro file ( File name ).

Specifies which column of *.pro file contains boundary data. If more columns define a boundary, this number specifies the first column containing boundary description. data.

TMF effect

Specifies the electric current and phase shift for the heater. The heater will be treated also like the inductor in the travelling magnetic field model (TMF) for computation of the Lorentz force acting on the melt. See for more detail Definition of the TMF inductors.

Related Procedures

Boundary Conditions