Elmer Integration (GSoC) - Activity Log

[bernd]

Hi,
I would like to ask you a question if it's possible to calculate and simulate the following effect, I don't know how to call this effect, and sorry for my lala English. I guess it's friction electricity.
I did sandblasting, and they forgot to install a ground / earth cable. Workers normally wear special isolating shoes.
There was so much voltage generated during sandblasting, I had to stopped because of pain in my hand and finger.
Air pressure was 6bar, and it was not Sand it was glas ball.
Thank you so much for an answer.
Best regards
Wilfried

Wilfried, with such an special question you'd better make a new topic ... I'm structural engineer means I can not help at all in this regard.

Bernd

[bernd]

might be interested for elmer guys because you are able to import Elmer results by gui too. https://forum.freecadweb.org/viewtopic.php?f=18&t=27426

[thschrader]

Hi,
I am trying to do a elmer-tutorial (flow over a step).
When writing the case, I get a boundary adressing error.
what do I wrong?

elmerTest.FCStd

(532.4 KiB) Downloaded 71 times

OS: Windows 10
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13346 (Git)
Build type: Release
Branch: master
Hash: 22ee06de8441bfcc9fded2c6de4232d763fb11bc
Python version: 2.7.14
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.1.0
Locale: German/Germany (de_DE)

elmer_tutorial.JPG (52.53 KiB) Viewed 2479 times

run_report.JPG (46.48 KiB) Viewed 2479 times

solver.JPG (42.48 KiB) Viewed 2479 times

[thschrader]

Did a elmer-run with elasticity-card:
steel-beam 100x10x10 mm S235, fixed, loading 500 N -z-dir.
beam-theory: max-sigma 300 N/mm^2, z-deflection 0,95 mm.
elmer: max sigma 300000 N/mm^2 (due to writing-error by factor 1000 to sif-file),
displacement 0,952 mm ok.
EDIT: the displacement below is given in m, so all values must be divided by 1000

So far so good. Obviously I havent understand how to set the
boundary conditions for using Navier-Stokes .

sif_force_z.JPG (37.92 KiB) Viewed 2459 times

vonMises.JPG (172.05 KiB) Viewed 2459 times

deformation_z.JPG (126.52 KiB) Viewed 2459 times

[HoWil]

Hi,
I am trying to do a elmer-tutorial (flow over a step).
When writing the case, I get a boundary adressing error.
what do I wrong?

Hi Thomas,

Thanks for your effort in creating a tutorial for the elmer-related part of FC-FEM
Please see http://www.elmerfem.org/forum/viewtopic ... 2fa#p16971
Due to some internal changes in FC-FEM is the original model I posted in the Elmer-Forum no more working out of the box.
I will try to rerecate it and will post it here.

BR,
HoWil

[HoWil]

Did a elmer-run with elasticity-card:
...
EDIT: the displacement below is given in m, so all values must be divided by 1000

Please have a look at https://forum.freecadweb.org/viewtopic. ... il#p194595
There you will find some benchmarks/examples and some code which shows how to use the python package "quantities" to compare results from elmer with results from CCX.
BR,
HoWil

[HoWil]

Hi,
I am trying to do a elmer-tutorial (flow over a step).
When writing the case, I get a boundary adressing error.
what do I wrong?

I will try to rerecate it and will post it here.

Hi Thomas,

Attached you find my model. I am not 100% sure if all parameters are set correctly but at least it runs through in ~1200sec . You probably want to adjust the mesh after remeshing. Also consider checking the parameter for the fluid-material in the commandline:

Code: Select all

###############################################################
# Setting values in FreeCAD
###############################################################
App.ActiveDocument.FluidMaterial.Material
fm = App.ActiveDocument.FluidMaterial.Material
#Parameter for Air in FC- mm-System
fm['Density'] = '1.2 kg/m^3'
fm['KinematicViscosity'] = '1.5e-5 m^2/s'
fm['DynamicViscosity'] = '1.8e-5 kg/s/m'
fm['ThermalConductivity'] = '0.0257 W/m/K'
fm['CompressibilityModel'] = 'Perfect Gas'
fm['ReferencePressure'] = '1e5 N/m^2'
fm['SpecificHeatRatio'] = '1.4'

App.ActiveDocument.FluidMaterial.Material = fm
App.activeDocument().recompute()

Unfortunately, I have very little time for Fc in the near future.
Hope this helps you creating a short tutorial.
BR,
HoWil

Code: Select all

OS: Ubuntu 16.04.4 LTS
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.17.13452 (Git)
Build type: None
Branch: master
Hash: 34633c144de9133c1f9aeb7da783f369cae9bfaf
Python version: 2.7.12
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.1.0
Locale: English/UnitedStates (en_US)

Code: Select all

ELMER SOLVER (v 8.3) STARTED AT: 2018/03/25 22:21:19
ParCommInit:  Initialize #PEs:            1
MAIN: 
MAIN: =============================================================
MAIN: ElmerSolver finite element software, Welcome!
MAIN: This program is free software licensed under (L)GPL
MAIN: Copyright 1st April 1995 - , CSC - IT Center for Science Ltd.
MAIN: Webpage http://www.csc.fi/elmer, Email elmeradm@csc.fi
MAIN: Version: 8.3 (Rev: unknown, Compiled: 2018-03-23)
MAIN:  Running one task without MPI parallelization.
MAIN:  Running with just one thread per task.
MAIN:  HYPRE library linked in.
MAIN:  MUMPS library linked in.
MAIN: =============================================================

[HoWil]

When writing the case, I get a boundary adressing error.
what do I wrong?

Your are trying to use the boundary conditions of CFD-wb for Elmer! They are not compatible (jet?)!

Any progress on your Elmer-FEM-FC tutorial?

BR,
HoWil

[thschrader]

Any progress on your Elmer-FEM-FC tutorial?

Yep, at the moment I run an elmer-FEM-case. It is tutorial number 6, laminar flow
over a step. I ran the original 2D-case from the elmer-distribution to see if the installation works. No problem.
I rebuild the case in FC with gmsh. Your input-file from above was very helpful.
I will keep you updated. Sorry for my late reply, I am busy on job too atm.
Thomas

elmer.JPG (56.08 KiB) Viewed 2333 times

tutorial6.JPG (59.89 KiB) Viewed 2333 times

[HoWil]

I ran the original 2D-case from the elmer-distribution to see if the installation works. No problem.

As I remember there is a limitation of Elmer-FC-FEM regarding 2D-Meshes. I think it is a limitation of Elmer-Grid, but I am not 100% sure. So, it is not possible to simply recreate the original 2D-model from the Elmer-tutorials.
EDIT: That is why I have built it as thin 3D-model with appropriate boundary conditions on bottom and top face.

I will keep you updated. Sorry for my late reply, I am busy on job too atm.

; Thanks for your work.
BR,
HoWil