4.4. The Stokes equations

The Stokes equations generalize the simple example of the Poisson equation on various levels. First of all, the Stokes equations are a system of two partial differential equations, one for the velocity field and one for the pressure field. Secondly, the Stokes equations involve the velocity as a vectorial unknown. Additionally, particular care has to be taken in the choice of the used finite element spaces for the velocity-pressure discretization.

Therefore, the Stokes equations constitute a perfect example to progress from the simple Poisson equation to more complex problems.