14.2.2. Dependent Variables

Tables must contain at least one dependent variable, which typically represents a real physical quantity whose value depends on that of the independent variables in the table.

Boundary Condition Loads

The following dependent variables are supported for tables that specify boundary condition loads.

Boundary ConditionDependent Variable(s)Description
PressurePressureThe magnitude of pressure normal to a surface
Pressure components (Pressure_i, Pressure_j, Pressure_k)The X, Y, and Z components of a pressure vector.
TemperatureTemperatureThe temperature on the boundary
Thermal ConditionTemperatureThe internal temperature of the body
ConvectionTemperatureThe ambient temperature (or bulk temperature) of the fluid
Film CoefficientThe film coefficient along the boundary

Limitation:
  • Pressure tables can include either Pressure or pressure components (Pressure_i, Pressure_j, Pressure_k), but not both. The available pressure components depend on the dimensions of your model, as described in Pressure Components in 2D and 3D Models.

  • Temperature cannot be used as a dependent variable and an independent variable in the same table.

  • Tables for convection boundary conditions can include both Temperature and Film Coefficient as dependent variables. However, the Mechanical APDL solver only uses one of these variables, depending on whether you assigned the table as the temperature or film coefficient magnitude. The independent variables in the table apply in both cases.

    For example, suppose your table contains Temperature and Film Coefficient as dependent variables and Time as an independent variable. If you assign the table as the temperature on a convection boundary, the solver uses the Temperature values in the table and ignores the Film Coefficient values. The reverse is true if you assign the table as the film coefficient. In both cases, the solver uses the Time values in the table.

  • If you create a table with multiple dependent variables (such as Pressure and Film Coefficient), you can use this table to specify the magnitude of either a Pressure boundary condition or the Film Coefficient for a Convection boundary condition. However, the result from this scenario might not be logical, as you are applying a Film Coefficient table to Pressure or a Pressure table to Film Coefficient.


Dependent Variables for Mechanical APDL Scripts

The following dependent variables are supported only for use with *DIM in Mechanical APDL scripts (run via Commands (APDL) worksheets).


Note:  The dependent variables listed under Boundary Condition Loads can also be used with the *DIM command in Mechanical APDL scripts.


Strain Scaling Factor Tables

The dependent variable Strain Scaling Factor is only used by the LPBF Process Add-on for additive manufacturing simulations. The Mechanical APDL solver ignores this variable for other simulation types.