TELEMAC¶

Since its early development, TELEMAC has become a robust an reliable tool for the numerically modelling of open surface flows. Yet there are a few little challenges and this page provides some answers (under development).

Traceback errors¶

If a simulation crashes and it is not clear why, debugging with gdb is a good option. To do so, first install gdb:

sudo apt install gdb

Then launch the steering file in debugging mode as follows:

telemac2d.py -w tmp simulation_file.cas --split    telemac2d.py -w tmp simulation_file.cas -x    cd tmp    gdb ./out_telemac2d

In gdb tap:

(gdb) run

To end gdb tap:

(gdb) quit

This approach also works with Telemac3d (and other modules).

Errors in Steering (CAS) Files¶

make sure to use : rather than =
place all model files in the same folder and only use file names without the directories of files

Instable Simulations¶

To increase model stability, modify the following variables or make sure that the variables are within reasonable ranges in the CAS file:

FREE SURFACE GRADIENT - the default is 1.0, but it can be reduced to 0.1 to achieve stability (nevertheless, start with going incrementally down, such as a value of 0.9).
IMPLICITATION FOR DEPTH should be between 0.5 and 0.6.
IMPLICITATION FOR VELOCITIES should be between 0.5 and 0.6.
IMPLICITATION FOR DIFFUSION should be 1. or smaller.

Errors in Mesh Files¶

3d-Meshing

A 3d simulation may crash when it is used with the parameter CHECKING THE MESH : YES. Thus, in 3d, favourably use ``CHECKING THE MESH : NO``.

To verify if TELEMAC can read the mesh, load the TELEMAC environment, for example:

cd ~/telemac/v8p2/configs
source pysource.openmpi.sh
config.py

The go to the directory where the mesh to be checked lives and run mdump, for example:

cd ~/telemac/studies/test-case/
mdump mesh-to-test.med

Until the time of writing this tutorial, mdump asks for input variables in French, which mean the following:

Mode d’affichage de noeuds? which means in English: Node display mode?
- Option 1: Interlaced mode
- Option 2: Non-interlaced mode
Connectivité des éléments? which means in English: Element connectivity?
- Option 1: Nodal
- Option 2: Descending
Il y a 1 maillage(s) de type local dans ce fichier. Lequel voulez-vous lire (0 pour tous|1|2|3|…|n)? which means in English: There is 1 local mesh(es) in this file. Which one do you want to read (0 for all or |1|2|3|…|n)?
- Option 0: Read all
- Option i: Read mesh number i

A standard answer combination of 1 - 1 - 0 will result in a console print of all nodes and connections between the nodes in the mesh, given that TELEMAC is able to read the mesh file. Starting with:

(**********************************************************)
(* INFORMATIONS GENERALES SUR LE MAILLAGE DE CALCUL N°01: *)
(**********************************************************)

- Nom du maillage : <<Mesh_Hn_1>>
- Dimension du maillage : 2
- Type du maillage : MED_NON_STRUCTURE
- Description associee au maillage :

(**********************************************************************************)
(* MAILLAGE DE CALCUL |Mesh_Hn_1| n°01 A L'ETAPE DE CALCUL (n°dt,n°it)=(-01,-01): *)
(**********************************************************************************)
- Nombre de noeuds : 243
- Nombre de mailles de type MED_SEG2 : 80
- Nombre de mailles de type MED_TRIA3 : 404
- Nombre de familles : 15

[...]

What does this mean? If mdump can read the mesh, the mesh file itself is OK and potential calculation errors stem from other files such as the steering file or the boundary conditions. Otherwise, revise the mesh file and resolve any potential issue.

SALOME-HYDRO¶

SALOME-HYDRO not starting (Kernel/Session)¶

If an error message is raised by Kernel/Session in the Naming Service (typically ends up in [Errno 3] No such process ... RuntimeError: Process NUMBER for Kernel/Session not found), there are multiple possible origins that partially root in potentially hard-coded library versions of the installer. To troubleshoot:

Manually create copies of newer libraries with names of older versions. For instance,
- In the 4th line after running ./SALOME, Kernel/Session may prompt error while loading [...] libSOMETHING.so.20 cannot open [...] No such file or directory
- Identify the version installed with whereis libSOMETHING.so.20 (replace libSOMETHING.so.20 with the missing library); for example, this may output /usr/lib/x86_64-linux-gnu/libSOMETHING.so.40
- Create a copy of the newer library and rename the copy as needed by SALOME; for example, tap sudo cp /usr/lib/x86_64-linux-gnu/libSOMETHING.so.40 usr/lib/x86_64-linux-gnu/libSOMETHING.so.20
- Most likely, the following files need to be copied:

sudo cp /usr/lib/x86_64-linux-gnu/libmpi.so.40 /usr/lib/x86_64-linux-gnu/libmpi.so.20
sudo cp /usr/lib/x86_64-linux-gnu/libicui18n.so.63 /usr/lib/x86_64-linux-gnu/libicui18n.so.57
sudo cp /usr/lib/x86_64-linux-gnu/libicuuc.so.63 /usr/lib/x86_64-linux-gnu/libicuuc.so.57
sudo cp /usr/lib/x86_64-linux-gnu/libicudata.so.63 /usr/lib/x86_64-linux-gnu/libicudata.so.57
sudo cp /usr/lib/x86_64-linux-gnu/libnetcdf.so.13 /usr/lib/x86_64-linux-gnu/libnetcdf.so.11
sudo cp /usr/lib/x86_64-linux-gnu/libmpi_usempif08.so.40 /usr/lib/x86_64-linux-gnu/libmpi_usempif08.so.20
sudo cp /usr/lib/x86_64-linux-gnu/libmpi_java.so.40 /usr/lib/x86_64-linux-gnu/libmpi_java.so.20
sudo cp /usr/lib/x86_64-linux-gnu/libmpi_cxx.so.40 /usr/lib/x86_64-linux-gnu/libmpi_cxx.so.20
sudo cp /usr/lib/x86_64-linux-gnu/libmpi_mpifh.so.40 /usr/lib/x86_64-linux-gnu/libmpi_mpifh.so.20
sudo cp /usr/lib/x86_64-linux-gnu/libmpi_usempi_ignore_tkr.so.40 /usr/lib/x86_64-linux-gnu/libmpi_usempi_ignore_tkr.so.20

Overwrite the SALOME-HYDRO’s internal version of Qt:
- Copy /usr/lib/x86_64-linux-gnu/libQtCore.so.5
- Paste in /SALOME-V2_2/prerequisites/Qt-591/lib/ - confirm replacing libQtCore.so.5

GUI/Qt5 support (GTK version compatibility)¶

With the newer versions of the Qt platform any menu entry in SALOME-HYDRO will not show up. To fix this issue, install and configure qt5ct styles:

sudo apt install qt5-style-plugins libnlopt0
sudo apt install qt5ct
Configure qt5ct (just tap qt5ct in Terminal)
- Go to the Appearance tab
- Set Style to gtk2 and standard dialogs to GTK2
- Click on Apply and OK
Open the file ~/.profile (e.g. use the file browser, go to the Home folder and pressing CTRL + H to toggle viewing hidden files) and add at the very bottom of the file:

export QT_STYLE_OVERRIDE=gtk2
export QT_QPA_PLATFORMTHEME=qt5ct

Save and close .profile and reboot (or just re-login).

Note

If a file called ~/.bash_profile (or ~/.bash_login) exists, the above lines should be written to this ~/.bash_profile/~/.bash_login because in this case, .profile will not be read when logging in.

Learn about Qt more at archlinux.org and in the arch wiki.

Hydro-Informatics