Search found 10 matches

by MTrevers
01 Oct 2017, 16:04
Forum: Elmer/Ice
Topic: Problem with the Coulomb sliding law
Replies: 6
Views: 8390

Re: Problem with the Coulomb sliding law

Hi Olivier,

I've tested this properly now, with the effective pressure variable defined correctly. I now get the same behaviour with or without the Cauchy stress from the first iteration, as expected. Also, the NS iterations converge nicely in both scenarios.

Thanks for your help
Matt
by MTrevers
30 Sep 2017, 22:47
Forum: Elmer/Ice
Topic: Problem with the Coulomb sliding law
Replies: 6
Views: 8390

Re: Problem with the Coulomb sliding law

Hi Olivier Without the variable: yes, the results are very different after the first steady state iteration. As before, they converge towards the same solution with multiple iterations. I haven't tested with the Effective Pressure variable yet (I made a mistake with the direction of gravity) and it'...
by MTrevers
24 Sep 2017, 19:51
Forum: Elmer/Ice
Topic: Problem with the Coulomb sliding law
Replies: 6
Views: 8390

Re: Problem with the Coulomb sliding law

Hi Olivier

Sorry about the delay in getting back to you over this. Where would you recommend I define the effective pressure variable? I've tested the new code without this variable and I still get different output for the first iteration.

Thanks
Matt
by MTrevers
29 Aug 2017, 22:54
Forum: Elmer/Ice
Topic: Problem with the Coulomb sliding law
Replies: 6
Views: 8390

Problem with the Coulomb sliding law

I've come across a problem when applying the Coulomb sliding law to my simulation. The output is completely different when setting the Cauchy flag on or off (which I know shouldn't be the case). With the flag set to False, the flow solution doesn't converge. When True, it does but the results are co...
by MTrevers
28 Aug 2017, 22:12
Forum: Elmer/Ice
Topic: Output basal drag and effective pressure
Replies: 3
Views: 6562

Re: Output basal drag and effective pressure

Thanks Thomas!
by MTrevers
11 Aug 2017, 22:37
Forum: Elmer/Ice
Topic: Output basal drag and effective pressure
Replies: 3
Views: 6562

Re: Output basal drag and effective pressure

I've tried the following... Under the body forces (BF3 refers to the basal boundary): Body Force 3 Zb Accumulation = Real 0.0e0 BDrag = Variable Coordinate 2 Real Procedure "ElmerIceUSF" "SlidCoef_Contact" End Then, a new solver: Solver 11 Exec Solver = Always Equation = Result O...
by MTrevers
09 Aug 2017, 21:44
Forum: Elmer/Ice
Topic: Output basal drag and effective pressure
Replies: 3
Views: 6562

Output basal drag and effective pressure

My problem ought to have a fairly straightforward solution. The Friction_Coulomb function calculates the basal drag (BDrag) and effective pressure (Ne). I'd simply like to be able to output these values into my .vtu files. Could somebody please show me how this is done? .sif file attached, it's pret...
by MTrevers
18 Nov 2015, 18:28
Forum: ElmerSolver
Topic: Solvers active at alternating timesteps?
Replies: 2
Views: 2498

Re: Solvers active at alternating timesteps?

Good point, I had just assumed that MATC handled maths like c.

I've built a very simple user defined function. Problem solved! Thanks!
by MTrevers
18 Nov 2015, 17:37
Forum: ElmerSolver
Topic: Solvers active at alternating timesteps?
Replies: 2
Views: 2498

Solvers active at alternating timesteps?

I'm trying to condition some solvers to be active only on odd or even timesteps From this thread, I came across the concept of an Exec Condition : http://www.elmerfem.org/forum/viewtopic.php?f=15&t=3115 Assuming this works like other conditions (i/e positive = on, negative = off), I expected the...
by MTrevers
17 Nov 2015, 16:09
Forum: ElmerSolver
Topic: Beginner question: FreeSurfaceSolver in two dimensions
Replies: 0
Views: 2316

Beginner question: FreeSurfaceSolver in two dimensions

Hi All, I'm currently trying to get to grips with Elmer/Ice. To help me learn how to put together .sif files, I've been trying to set up the very simple case of a narrow 2D column of ice deforming under the pressure of it's own weight, with no external forcings. I've decided to adapt Thomas' simple ...