dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Thu, May 19, 2011 at 03:46:03PM -0000, Kyle wrote:
> Question #158012 on DOLFIN changed:
> https://answers.launchpad.net/dolfin/+question/158012
>
>     Status: Answered => Open
>
> Kyle is still having a problem:
> I want the pressure and velocity values at all nodes along a boundary so
> that I can compute the stress tensor and multiply it by the stress
> normal. With the computed stress I would like to apply them to their
> corresponding node on the solid mesh to solve the elasticity equation.

Yes, but which type of function space do you have? If you have
piecewise linears, you only need to get the values at the vertices
(which is easy). If you have quadratics, then you need the edges,
which is also easy. If you have higher order, then it gets more tricky
and you would have to follow the recipee by Kristian.

If you're interested, you can have a look in the cbc.solve code
(available on Launchpad) where there is a simple FSI solver that does
exactly this: computing the stress from a P2-P1 Taylor-Hood
approximation of the fluid field and applying the force to a P1
structure problem.

--
Anders