Search found 4832 matches

by raback
24 Sep 2009, 12:27
Forum: Installation & compilation
Topic: Elmergrid installation
Replies: 1
Views: 4623

Re: Elmergrid installation

Hi Haibo ElmerGrid is a command-line tool. You probably got the installation right but you just need to run it from your command prompt. The functionality of ElmerGrid is for the most parts build in also in the ElmerGUI plug-in. Elmer suite does not include any geometry creation tools. Simple geomet...
by raback
24 Sep 2009, 09:38
Forum: ElmerSolver
Topic: Poisson solver and "BC" across dielectric media.
Replies: 5
Views: 11565

Re: Poisson solver and "BC" across dielectric media.

Hi Roberto You should decleare two different bodies so that you can assign them different material parameters. Other than that I don't think you have to do anything as the continuity of the flux over the boundary is always maintained (in a weak sense). If your box is exactly as you describe and the ...
by raback
22 Sep 2009, 13:17
Forum: General
Topic: scaling a mesh
Replies: 1
Views: 4472

Re: scaling a mesh

Hi John, Unfortunately scaling is not directly supported by ElmerGUI or ElmerSolver. This would be easily implemented and maybe will be done so in the future. ElmerGrid can read in meshes and write them with a different scaling when you give the command line arguments '-scale cx cy cz' where the thr...
by raback
17 Sep 2009, 20:59
Forum: General
Topic: Beginner's Instruction Guide for Dummies? Where?
Replies: 1
Views: 5459

Re: Beginner's Instruction Guide for Dummies? Where?

There is no such guide. One challenge in multiphysical codes is that users are interested in a large variety of things. Stress computation and Vertex already limit the field so much that it might not fit into a Elmer for Dummies guide. Anaway, quickly browsing through Vertex homepage there seems to ...
by raback
17 Sep 2009, 20:51
Forum: ElmerSolver
Topic: Reaction forces in stress solve
Replies: 2
Views: 4788

Re: Reaction forces in stress solve

You might apply the same methodolgy as with the computation of drag. Didn't test though but it should work if the default linear system wrapper is used witin the solver... You may compute the residual of the discrete system r=Ax-b where A does not include the effect of BCs. For stress solver the res...
by raback
16 Sep 2009, 23:31
Forum: General
Topic: drag calculation
Replies: 1
Views: 5582

Re: drag calculation

The are two different ways. 1) The more accurate and consistant one uses the residual of the discrete system r=Ax-b where A does not include the effect of BCs. For Navier-Stokes equation the residual includes the nodal force vectors needed to reproduce the flow field. To activate the computation add...
by raback
16 Sep 2009, 20:05
Forum: ElmerSolver
Topic: How to plot scalars at edge using arc lengths
Replies: 3
Views: 5460

Re: How to plot scalars at edge using arc lengths

The syntax you wrote should work. Are you sure that the two line segments you define really go through some element faces? In 2D you should just define the x and y coordinates and the lines should go through element edges. There has been cases when the subroutine has not worked that well. These are ...
by raback
15 Sep 2009, 21:45
Forum: General
Topic: Helmholtz+Heat Eqn
Replies: 1
Views: 4199

Re: Helmholtz+Heat Eqn

Hi Selim I wonder if I could couple the Helmholtz equation with the Convective heat transfer equation. You can introduce some coupling. For example, the sound speed and convection velocity of the Helmholtz equation may be given. There are some underlaying assumptions and to honor them I think that t...
by raback
15 Sep 2009, 21:19
Forum: ElmerSolver
Topic: How to add force on Nodal boundary condition
Replies: 1
Views: 3933

Re: How to add force on Nodal boundary condition

Hi Shawn Your syntax has at least the problem that you should decleare the type of the condition i.e. Boundary Condition 2 Target Nodes(1) = 31 Displacement 1 Load = Real 2000.0 End The reason for this is that even though 'Displacement 1' is a known keyword all the derived keywords are not defined i...
by raback
14 Sep 2009, 23:53
Forum: External tools
Topic: Concentric discs from ElmerGrid?
Replies: 2
Views: 4820

Re: Concentric discs from ElmerGrid?

Hi deorbit Unfortunately this may be tricky. Circular forms with structured mesh generation requires some tricks if one does not want to sacrifice the shape of the elements. In 2D no such tricks have been implemented. Mapping two concentric squares into two circles might be done but it would result ...