dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Tue, May 23, 2006 at 02:46:32PM +0000, Alexander Jarosch wrote:
> Hi,
> 
> did anyone play around with the stokes solver on more complex 
> geometries? I only seem to get something senseful using a stabalized 
> stokes like:
> 
> scalar = FiniteElement("Lagrange", "triangle", 1)
> vector = FiniteElement("Vector Lagrange", "triangle", 2)
> system = vector + scalar
> 
> (v, q) = TestFunctions(system)
> (u, p) = TrialFunctions(system)
> 
> f = Function(vector)
> h = Function(scalar)
> nu = Function(scalar)
> 
> beta  = 0.2
> delta = beta*h*h
> 
> a = (nu*dot(grad(v), grad(u)) - div(v)*p + q*div(u) + delta*dot(grad(q), 
> grad(p)))*dx
> L = dot(v + mult(delta, grad(q)), f)*dx
> 
> which is fine, but when I compare the solution to another FEM package, 
> they do not quite match. Was there already some benchmarking done?
> 
> cheers,
> 
> Alex

Do you really need to stabilize here? You're already using Taylor-Hood
elements anyway. Have you tried a stabilized equal-order method?
(Change 2 to 1 in the example above.)

I have only tested the Stokes solver on simple geometries and I
haven't compared to any other solvers.

/Anders