The General Interior Flux node, found under the More submenu, adds the most general interior boundary condition for the Nonlinear Pressure Acoustics, Time Explicit model, as it is formulated (in the conservative form) for the discontinuous Galerkin method (dG). The condition defines the normal flux g = [gp gu] at an interior boundary. It should include any necessary numerical flux (as it overrides the Numerical Flux). Care should be taken when using this advanced condition as the method is sensitive to proper formulation of boundary conditions.

Enter the expression for the components of the Flux vector gp and gu.