PDE 12: Cahn–Hilliard equation
This equation is a dissipative PDE
\[\frac{\partial u}{\partial t}=\frac{\partial^2 }{\partial_x^2}(p u+r u^3+qu_{xx}), \] where \( u=u(x,t)\) You could consider periodic boundary conditions.
Google: Cahn-Hilliard equation (!)
Challenges: non-linearity, high order derivatives.