Equations

You need a weak form equation (a differential equation using a weak formulation) for all features that contribute to the governing equations. The equation contributes to the weak form of representing the system of PDEs you want to solve for. You can enter the equations in these forms:

•	Directly as a weak form equation, which is the most general technique to specify an equation.

•	In the general form similar to the General from PDE interface in the Model builder.

•	In the coefficient form similar to the Coefficient PDE interface in the Model builder.

In this section:

•	Weak Form Equation

•	General Form Equation

•	Coefficient Form Equation

•	Shared Quantity Definition