open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,

I am a beginner Telemac2D user and I am working on a project consisting in modelling experimental urban flooding. I want to compare the results of a modelisation using Volumes Finite method and Element Finite method.
My computation with VF method works well(Pilote_Mesh_30k_14ES.cas) and give me coherent result. The problem is when I try to switch to a EF method (Pilote_30k_EF.cas), suddenly there are no inflows in my domain (but I don't change any parameter concerning the boundary condition).
It may be a silly error but I didn't find information in the user guide or in the forum to solve my problem. Does anybody ever encounter this situation and know how to fix it ?

I attached my files, so you can check the different doc.
Regards.

No files attached

oh my bad, this time it should be OK.

Hello Cyril,

In your steering file for the keyword VELOCITY PROFILES (PROFILS DE VITESSE in French), if you change the values 5 to 4, your FE computation runs.

Hope this helps,

Chi-Tuan

Hi,

I don’t know if I am supposed to create a new topic or not: the problem is different but the main theme is still the same.
Since the last post and your advice, the situation the situation evolved pretty well : I switched to the Finite Element equations because it gave better outputs and since I’ve developed my files to improve the parameters of the simulation and everythings works great (file : Pilote_90k_EF.cas - this file works great). With these changes I wanted to switch back to the Finite Volume method (file : Pilote_90k_EF.cas – file with problem) to see the difference.

The problem with the Finite Volume run are the following : I’ve got some outflows acting as inflows (2 outflows out of 14, number 10 and 13), and the inflows bring so much water that this is causing my run diverge at time step before 1-2-sec. I’ve check my .cli file and they are well setting as outflow, same for my steering files were no inflows are defined for these bc. Moreover this problem doesn’t happened in my Finite Element simulation. I don’t understand were the problem comes from.

Another problem : “ PROBLEME MAL POSE, VITESSE LIBRE ENTRANTE “ the point indicated is a wall with no particularity ( I checked in my cli file and in BlueKenue). And as the previous problem, this error doesn’t appear in the Finite Element simulation despite I use the same files.

I tried to modify the numerical parameters (file : Pilote_90k_VF_test.cas). To do so I adapted the ones from the dambreak examples. The problem with this run : it was extremely slow to run compared to my others runs (20h of calcul to simulate 15s), no more outflows acting as inflows except one outflow (number 7) was switching frequently (so no diverging), and the main problem : the run didn’t tend to the right solution I expected.

Do you have an idea why these problems occurs in the Volume finite run and not in the Element finite run ? And how could I solve theses problems

Hello Cyril,

Which release of TELEMAC-2D are you using? You seem to use a release older than v8p2.

My first advice is to use at least the latest release because there were a lot of work done for Finite Volumes in v8p2 in particular many bugs were fixed.

If you still face a problem, please use the trunk release as some bugs have been recently solved, in particular for boundary conditions:
Have a look at wiki.opentelemac.org/doku.php?id=installation_on_linux to see how to download the trunk release (URL + generic accoung + password):
Username ot-svn-public
Password telemac1*

Hope this helps,

Chi-Tuan

Hello pham,

Thank you for your response.
I was using the v7p2 version. As you advised, I switch to the v8p2r0 but the problems are still here. I will try to use the trunk version.

Best regards