Physics Nodes — Equation Section
For each physics node there is an Equation section always available on the Settings window. This has options to display mathematical equations applicable to the node.
The display options available from the lists depend on the study types and other physics-specific factors. See Figure 3-19 for an example comparing the equations that display for a Stationary or Time Dependent study for a Heat Transfer in Solids interface. Some Settings windows do not have any options and only display the relevant equation and other windows have additional sections that become available for the Equation display based on the study type selected.
Node Contributions Display a Dotted Line Under Part of the Equation
For all physics nodes (excluding the main physics interface node level), the equation that displays includes a dotted line underneath where the node’s contribution is made to the equation. See Figure 3-18 for an example where a section of the heat transfer equation is underlined, indicating where the Solid node contributes to it.
Figure 3-18: The Solid contribution to the equation for a 2D model.
Equation Form
When you add physics interfaces to a Component, the supported Study types are listed in the Equation form list. Study controlled is the default; select another option as needed. When the setting is Study controlled, the study controls the equation form — stationary or time dependent, for example — for the physics interface. In some cases, that equation form might not be compatible with the physics covered by the physics interface; the physics interface then uses its default equation form (typically, a stationary equation form). You can then instead choose one of the supported study types.
Show Equation Assuming
The Show equation assuming option is available by default when Study controlled is selected (or left as the default) as the Equation form. Options availability is based on the studies added and defined for the model.
For the following options — frequency and mode analysis frequency — you also have the option to use another frequency than the one used by the solver. This can be necessary if you need two different frequencies for two physics interfaces.
Frequency
This option is available if Frequency domain is selected as the Equation form. The default uses the frequency From solver. If User defined is selected, enter another value or expression (SI unit: Hz).
Mode Analysis Frequency
This option is available if Mode Analysis or Boundary Mode Analysis is selected as the Equation Form. Enter a value or expression in the field (SI unit: Hz). Specify a frequency (it is not present as a solver variable).
Port Name
This option is available with the RF Module Electromagnetic Waves interface and if Boundary Mode Analysis is selected as the Equation Form. Enter a value in the field (unitless).
Figure 3-19: An example of the Equation section on a Heat Transfer interface. Selecting the study type updates the equation accordingly.