[CIG-CS] Particle problems and Semi-Lagrangian Schemes for Gamr

[Wolfgang Bangerth]

> This is very interesting.  What do you mean that they are expensive in
> elements?  I would expect the cost of advection would be dwarfed by
> the cost of solving Stokes.

That's certainly the case for the deal.II mantle convection code. I
think I remember that the Stokes solver is about a factor of 6-10 more
expensive.

In your original mail, you had this statement:

> Because of the higher order Q2 elements, it takes
> literally hundreds of particles to get a solution accurate to a part
> in 10^3 in 2D.

Do you mean hundreds of particles *per cell*? And what is the measure by
which you compute accuracy?

Best
 W.