Elmer Discussion Forum

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...

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...

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...

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...

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 ...

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...

Some comments: 1. The plate solver (the module SMITC) doesn't model the stretching of the mid-surface (the bending is only considered) and therefore one may apply a distributed normal load only. The shell solver can model the bending and stretching effects simultaneously and would allow to handle mo...

Hi, To avoid the error (message) one could remove the command "Flow Interface = Logical True" and write a flux BC for the Helmholtz model in terms of the velocity. On the other hand giving the error in this case appears to be unnecessary. I think the Helmholtz code would create a right BC ...

Hi,

I think the vectorial Helmholtz solver doesn't read any keyword starting as "Inverse ...". Some earlier version perhaps did which may be the source of confusion. I believe the keywords described in Models Manual work.

-- Mika

I converted your mesh file as ElmerGrid 8 2 body.unv -autoclean and then run the case under a debugger (with "Quadratic Approximation = True" added) which didn't find anything suspicious. The mesh conversion however gives a geometry model which has just one group of boundary elements while...