Use the Monopole Domain Source node to add a user-defined domain source term Qm to the governing equation. A monopole domain source added to a domain has a uniform strength in all directions. In advanced models, this source term can, for example, be used to represent a domain heat source causing pressure variations or a user defined nonlinear contribution to the equations in the time domain. Add this node from the More submenu.

Dedicated features define advanced domain sources of the monopole type, such as the Heat Source or the Flame Model. In the time domain there is the Nonlinear Acoustics (Westervelt) Contributions.

Enter a Monopole domain source Qm (SI unit: 1/s2). This can be any user defined expression or constant.