The nodes available from the Classical PDEs submenu can be added to any PDE interface at the domain level. The same node is also available as its own interface from the Mathematics>Classical PDEs branch () when adding an interface.

The Laplace Equation is a classic PDE of elliptic type that can describe the behavior of some kind of potential or the steady-state heat equation.

The Poisson’s Equation is a classical PDE of elliptic type that can describe, for example, electrostatics with a space charge density.

The Helmholtz Equation is a classical PDE of elliptic type that can represent, for example, a time-independent form of the wave equation.

The Wave Equation is a classic PDE of hyperbolic type. It is a second-order PDE that describes waves, such as sound waves, light waves, and water waves.

The Heat Equation is a classical PDE of parabolic type that describes time-dependent heat transfer by diffusion or other diffusion processes.

The Convection-Diffusion Equation is a classical PDE that describes time-dependent transport by convection and diffusion.