dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

Something went wrong at changeset 4224,

  http://www.fenics.org/hg/dolfin?cs=c5a7da38ff2c

Garth

ndl@xxxxxxxxxxxxxx wrote:
> On Monday 16 June 2008, Anders Logg wrote:
> > On Mon, Jun 16, 2008 at 05:40:00PM +0100, Nuno David Lopes wrote:
> > > Is this problem really solved?
> > No, it looks awful here as well. It used to look much better.
> >
> > > I'm get oscillating spikes  all over the boundary.
> > > The same for a standard 2d cavity.
> > For which element types are you getting the spikes?
> in 2D the same as in demo: triangle 
> Lagrange 2 for velocities and Lagrange 1 for pressure.
>
> > > Also in 3d experiments.
> > > I'm getting  the feeling that only the the dofs associated with the
> > > triangle vertices are getting the boundary conditions, (or something like
> > > that is happening.)
> > Can you check for which degrees of freedom we are enforcing
> > boundary conditions? Are we missing any?
> I will try to get into that  first thing tomorow. I hope i'll understand it!!!
> I think I've seen  something similar some time ago, don't remember if it was 
> in my old hand-made c++  codes, using Uzawa methods, 
> or in FreeFem++ also with Uzawa methods, 
>  but i've solved it and I really don't remember what was the problem.