Solving the Stokes system twice in a single time step with different boundary conditions

Hi all,

I would like to find out if the following workflow I have in mind is feasible to implement in Aspect at the moment. So for every time step, this basically happens:

  1. Solve the Stokes’ equations with one set of boundary conditions (BCs) over the whole domain to obtain one set of velocity solutions (let’s call this A).
  2. Use A to perform some calculations to get a second set of BCs.
  3. Solve the Stokes’ equations again but with the abovementioned BCs to obtain a second set of velocity solutions (let’s call this B).
  4. Combine A and B to advect the relevant fields to the next time step.

I am interested to find out if such a scheme is supported at the moment by a plugin for instance or will it likely to involve heavy tinkering to the simulator if it is not.

Kang Wei

Kang Wei – I think that’s a difficult setup to make work in ASPECT without a lot of internal modifications. You’d in essence have to fork the ASPECT code base to make that work.

But, my experience is that it’s worth starting not with how you want to do something, but with what it is and why. Can you explain what problem you are trying to solve and why it requires two Stokes solves? Maybe we can find a different way to achieve what you are looking for, before we think about how to implement it!