The Initial Values node adds initial values for the sound pressure and the pressure time derivative that can serve as an initial guess for a nonlinear solver. 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 the Pressure, first time derivative, ∂p/∂t (SI unit: Pa/s). The defaults are 0 Pa and 0 Pa/s, respectively.