## Search found 77 matches

03 Jan 2022, 13:20
Forum: Elmer/Ice
Topic: Problems with basal sliding when applying Porous Solver
Replies: 7
Views: 6751

### Re: Problems with basal sliding when applying Porous Solver

Dear Gleb,

The form of the friction law here is linear, i.e. \tau_nt = C u_t where C is the "Porous Slip Coef t", for t = 1 and 2. If you want to use more complex friction laws, you should have a look on the wiki in User Functions (Weertman, Coulomb, Budd).

Hope it helps,
Olivier
27 Mar 2021, 13:32
Forum: Elmer/Ice
Topic: Numerical instabilities (spikes in the ice surface) at grounding line
Replies: 4
Views: 5843

### Re: Numerical instabilities (spikes in the ice surface) at grounding line

Hi Clara,

Did you try to decrease your time step?

Also, having a water pressure dependent friction law might help by removing the discontinuity at the GL.

Hope it helps
Olivier
24 Mar 2021, 12:23
Forum: Elmer/Ice
Topic: Numerical instabilities (spikes in the ice surface) at grounding line
Replies: 4
Views: 5843

### Re: Numerical instabilities (spikes in the ice surface) at grounding line

Helo,

Can you be more specific? Are you running a Stokes or a SSA simulation? 2d or 3d? From which setup did you started?

Regards,
Olivier
10 Feb 2021, 13:48
Forum: Bug reports
Topic: Dirichlet condition in the body force section
Replies: 0
Views: 5489

### Dirichlet condition in the body force section

Hello, When executing a solver on the boundary of the bulk mesh (e.g. the free surface solver), the Dirichlet boundary conditions imposed in the Body Force section associated to this second body are not imposed. The problem is in the SolverUtils routine where the loop is only done over NumberOfBulkE...
08 Jan 2021, 19:21
Forum: ElmerSolver
Replies: 3
Views: 2057

### Re: VariableAddVector - elmental variable

Thanks Peter!

One more question regarding elemental variable. Are they supported for Restart procedure (writing and reading in .result)?

Thanks again
Olivier
07 Jan 2021, 23:30
Forum: ElmerSolver
Replies: 3
Views: 2057

Hi, When creating a variable from a solver, one can use the VariableAddVector subroutine: SUBROUTINE VariableAddVector( Variables,Mesh,Solver,Name,DOFs,Values,& Perm,Output,Secondary,VarType,Global,InitValue,IpPoints) By default it will create a nodal value. Which value should be given to VarTyp...
05 Nov 2020, 22:37
Forum: Elmer/Ice
Topic: 2-D Flow line Model
Replies: 2
Views: 4587

### Re: 2-D Flow line Model

Hello, The problem is that you have zero thickness at the front of the glacier and that you should take care that the mesh has a minimum height by setting Minimum Mesh Height = Real 1.0 Correct Surface = Logical True in the Solver section of StructuredMeshMapper. Moreover, for a 2d flow line problem...
15 Oct 2020, 09:17
Forum: ElmerSolver
Topic: There are no Solvers in the System
Replies: 4
Views: 3253

### Re: There are no Solvers in the System

Hello, In section "Equation 1", there is no solver indicated! You should have a line of that type in this section Active Solvers (1)= 1 But also you should have at least one solver section which tells which equation you are solving! See examples in /elmerfem/fem/tests of the source code. R...
31 Jan 2020, 14:56
Forum: Elmer/Ice
Topic: Time step dependency for Stokes grounding line
Replies: 5
Views: 8039

### Re: Time step dependency for Stokes grounding line

Hi Cyrille and Martin, What would be great is that you test the fixes proposed by Brandon Berg and Jeremy Bassis on your setups to see if it changes the dependence to time step of your simulations? My understanding of this fix is that you simply need to reintroduce the acceleration term in the force...
29 Jan 2020, 11:08
Forum: Elmer/Ice
Topic: Time step dependency for Stokes grounding line
Replies: 5
Views: 8039

### Time step dependency for Stokes grounding line

Hi all, You may have seen this paper in TCD ( https://www.the-cryosphere-discuss.net/tc-2019-315/ ) by Brandon Berg and Jeremy Bassis regarding the "time step dependence (and fixes) in Stokes simulations of calving ice shelves". As they are solving the contact problem in the same way as us...