A dependent variable needs an initial value for nonlinear and transient simulations. In the Initial Values node (
) you define the initial value for the dependent variable declared in the parent node. This node represents a special type of feature in the Model Builder that you get by default when you add a physics interface.
) you define the initial value for the dependent variable declared in the parent node. This node represents a special type of feature in the Model Builder that you get by default when you add a physics interface.In the Settings window of the variable you specify the initial value in the Default initial expression field. The expression you enter here follow the rules outlined in Entering Names and Expressions, but with an exception. If you use a variable name here, you must specify the scope it uses. As an example, assume that you want to use the interface variable init as initial condition, then enter phys.init in the expression field. Otherwise, the initial value expression becomes init, and at solution time this gets a component scope. Select the Set initial value on time derivatives check box to activate the initial values for the first time derivative. In the Geometric entity level list, choose the entity level that the initial value is placed on. This must match the entity level you put the dependent variable definition on.