Search found 230 matches

by mika
19 Jan 2022, 19:52
Forum: ElmerSolver
Topic: Problem with transient heat transfer
Replies: 9
Views: 1316

Re: Problem with transient heat transfer

Do you maybe have some further ideas to better physically introduce the flux in FEM methods that I could try out? If not, do you then suggest to check out finite volumes for these types of problems? I believe the mixed FEM formulation presented in the section "Mixed Approximation of the Poisso...
by mika
14 Dec 2021, 10:27
Forum: ElmerSolver
Topic: Modelpde with no stabilization
Replies: 3
Views: 830

Re: Modelpde with no stabilization

In Elmer the basic element definition for using the p-version of FEM is just "p:k", where k defines the order of approximation. Elmer then assigns automatically the right numbers of DOFs associated with different geometric entities (edges, faces and element interiors). Mixing the definitio...
by mika
09 Dec 2021, 19:16
Forum: ElmerSolver
Topic: Modelpde with no stabilization
Replies: 3
Views: 830

Re: Modelpde with no stabilization

It should be possible to apply bubble augmentation by giving a p-element definition. For example

Element = "p:1 b:1"

creates one elementwise bubble function. This construct doesn't depend on the keyword Bubbles and needs the background mesh consisting of the lowest-order elements.

--Mika
by mika
08 Sep 2021, 16:02
Forum: ElmerGUI
Topic: Magnetization
Replies: 7
Views: 3004

Re: Magnetization

Rich_B wrote: 08 Sep 2021, 15:45 The WhitneyAVsolver is the only solver that uses edge elements, correct?
The modules EMWaveSolver and VectorHelmholtz for electromagnetic waves also use edge finite elements.

-- Mika
by mika
05 Sep 2021, 13:29
Forum: Software development
Topic: GOLF rheology in ParStokes Solver?
Replies: 8
Views: 5231

Re: GOLF rheology in ParStokes Solver?

I committed changes which should be quite close to what are needed here, see https://github.com/ElmerCSC/elmerfem/commit/8b78545b963eae289b74320b9fc91bb298d39eba and a small fix https://github.com/ElmerCSC/elmerfem/commit/9a9a5e3537b14a7546b7dd2f99a1d4678d1e4c05 I followed the convention that the st...
by mika
01 Sep 2021, 09:49
Forum: Software development
Topic: GOLF rheology in ParStokes Solver?
Replies: 8
Views: 5231

Re: GOLF rheology in ParStokes Solver?

I think the book mentioned in the paper doesn't really treat anisotropy. If you can create a code which enables to represent the material law as T + p I = C^{ijkl}D_{kl}, with the righ-hand side expressed by using the Voigt notation (that is, the tensor C is then expected to be a (6x6)-matrix), I co...
by mika
30 Aug 2021, 15:53
Forum: Software development
Topic: GOLF rheology in ParStokes Solver?
Replies: 8
Views: 5231

Re: GOLF rheology in ParStokes Solver?

Yes, I also think that using the average of the diagonal entries of the constitutive operator may be the simplest strategy so that the scalar viscosity parameter can be used in the pressure preconditioner. Did you find any article where this strategy is applied, so that one would know beforehand how...
by mika
24 Aug 2021, 10:14
Forum: Software development
Topic: GOLF rheology in ParStokes Solver?
Replies: 8
Views: 5231

Re: GOLF rheology in ParStokes Solver?

Here an open question is to identify an effective approximation to the Schur complement (the coefficient matrix for the pressure updates in the preconditioning). The current choice is designed for a scalar viscosity and the generalization to anisotropy seems to be a research topic. Other modificatio...
by mika
07 Jun 2021, 22:01
Forum: Software development
Topic: Edge degrees of freedom
Replies: 8
Views: 8392

Re: Edge degrees of freedom

in general ElmerSolver can use only one variable within the whole domain? Would it be possible to implement something similar within the AT-Solver module or would such an option require changes within the Elmer source code? This is not possible, since the unknown of a PDE model is supposed to have ...
by mika
25 May 2021, 11:28
Forum: ElmerGUI
Topic: Disk deflection calculation
Replies: 10
Views: 4772

Re: Disk deflection calculation

Let U_(+)(x,y,b) and U_(-)(x,y,-b) denote the displacement vectors on the upper and lower faces of the shell. Then the three components of DNU could be computed as the components of the vector [U_(-)(x,y,-b) - U_(+)(x,y,b)]/(2b) with respect to the global frame. Thus no norms ||.|| are involved in t...