The Initial Values node adds and initial value for the pressure. In the time domain it also adds and initial value for the pressure time derivative. The initial values can serve as an initial guess for a nonlinear solver or describe the initial state that will then evolve in time. If more than one initial value is needed, from the Physics toolbar click to add more Initial Values nodes.

Enter a value or expression for the initial values for the Pressure p (SI unit: Pa) and, in the time domain, also for the Pressure, first time derivative, ∂p/∂t (SI unit: Pa/s).