open TELEMAC-MASCARET The mathematically superior suite of solvers

Hello,
I am testing the new GAIA module in a coastal environment. So far it seems to produce qualitatively similar, albeit underestimated, results to SISYPHE using the Watanabe total load formula. I do not know how much of SISYPHE overestimation can be attributed to rounding errors from setting high 'zero' thresholds in subroutine 'layer'.
Next step was to employ the Soulsby & van Rijn suspension formula. Initially, I was puzzled by the absence of the 'D90' variable in the dico while it is documented in the manual. Then I run the case anyway, only to fail with the following error:Is the development of this formula still ongoing?
Best Regards,
Costas

Hello Costas,
Many thanks, we will take a closer look to that.
Please be aware that the current version of Gaia -already available in the trunk- is still underway (including documentation, test cases, etc.).
Don't hesitate to send us further comments and feedback for improvements/bug corrections.
Best wishes,
Pablo (on behalf of the development team of Gaia).

Hello Pablo,
I understand that it is still under development, but I am looking forward to its release and the least I can do is test and report.
If possible, rename the topic to something generic, like "GAIA feedback", and I will post all my comments here.
Costas

Next step was BJIKER formula. Nothing changed from the previous run except:It produced the following error:

Other lesser issues are:

• When continuing a computation is that if the prerequisite variables are missing from the previous result file (*Si in my case), the code just crashes without explanation. This pre-requisite is documented though.
• Regarding sediment slide: When setting FRICTION ANGLE OF THE SEDIMENT to a slope similar but steeper than my existing geometry slope, the code hangs from the first timestep. For example (T3 element average in Blue Kenue reports) 15.5 degrees maximum slope and FRICTION ANGLE OF THE SEDIMENT 15-18 hangs. 20 degrees work.

Update: FRICTION ANGLE OF THE SEDIMENT = 20 and the computation hangs later on, so had to disable SEDIMENT SLIDE to keep the model robust.

Hello,

Can anyone confirm that the quantity measured by fluxlines in GAIA, is pure kg of sediment? A remark in the manual would also be helpful. :)
Best Regards,
Costas

Hello Costas,

Yes it should be kg/s and kg.
There is no test-case with fuxline in GAIA... Is your results obtained with fluxline are consistent with the global (bed) mass balance (MASS-BALANCE = YES)?

Thanks a lot for your feedback.

Best regards,
J

Hello Jacques,
Thank you for your confirmation. I cannot check the mass balance since I haven't setup fluxlines at the boundaries , as it never really helped with SISYPHE. With GAIA's MASS BALANCE, I think I should setup a check mechanism with fluxlines.
Costas

Dear Costas,

At the moment in GAIA the CSRATIO is only computed when using a Miles suspension profile (SETTLING LAG = TRUE), so if you try to use suspension_sandflow_gaia without it it causes this crash on purpose.
Best regards,
Agnès