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To whom it may concern,
I am simulating the turbidity current in the reservoir with Telemac3d and Gaia.
During the sensitivity analysis of critical shear stress for erosion and deposition.
I found that the same function could be defined in Telemac3d and Gaia.
Telemac:
'CRITICAL EROSION SHEAR STRESS OF THE MUD LAYERS'
'CRITICAL SHEAR STRESS FOR DEPOSITION'
Gaia:
'LAYERS CRITICAL EROSION SHEAR STRESS OF THE MUD'
'CLASSES CRITICAL SHEAR STRESS FOR MUD DEPOSITION'

I would like to know what is the difference between these keywords.
If those are the same, which one has a higher priority.

Moreover, I have already change the value of 'CLASSES CRITICAL SHEAR STRESS FOR MUD DEPOSITION' from 1000 to 0.0003, the results are the same.

I hope that someone could give me assistance to solve this problem.

Hello Chen,

As you may know, GAIA is the new sediment transport module that is currently developed. Previous modules to model sediment transport are still available in the TELEMAC system (SISYPHE and SEDI-3D for suspension in 3D). That is why you may find common keywords, used e.g. by GAIA, but not by SISYPHE or SEDI-3D (and vice-versa).

If you look at the telemac3d.dico or the TELEMAC-3D reference manual, the variables with the MNEMO prefix = S3D_ are used by SEDI_3D and not GAIA.
Thus if you use GAIA, CRITICAL EROSION SHEAR STRESS OF THE MUD LAYERS and
CRITICAL SHEAR STRESS FOR DEPOSITION should be useless and have no effect for your GAIA computations.

Hope this helps,

Chi-Tuan

Dear Prof. Chi-Tuan,

Thanks for the quick and useful reply.
I have learned that the critical shear stress for erosion and deposition cannot be defined in Gaia's steering file.

If I would like to modify the critical shear stress for erosion and deposition, I should set the value in Telemac3d's steering file('CRITICAL EROSION SHEAR STRESS OF THE MUD LAYERS'; 'CRITICAL SHEAR STRESS FOR DEPOSITION')?
Moreover, there is no information about the default value of 'CRITICAL EROSION SHEAR STRESS OF THE MUD LAYERS' in Telemac3d.dico.

Again, I appreciate the helpful information and kindly help.
If it is available, please revise the Gaia.dico and the reference manual.

Chen

Hello Chen,

Maybe I was not clear, I try to explain differently:

If you use GAIA coupled with TELEMAC-3D, the 2 keywords CRITICAL EROSION SHEAR STRESS OF THE MUD LAYERS and CRITICAL SHEAR STRESS FOR DEPOSITION available in the TELEMAC-3D steering file are not used, but the 2 keywords LAYERS CRITICAL EROSION SHEAR STRESS OF THE MUD and CLASSES CRITICAL SHEAR STRESS FOR MUD DEPOSITION available in the GAIA steering file are used.

You should then change the last 2 ones if using GAIA.

FYI, a new release (v8p2) is about to be tagged (in 1 month) and the GAIA dictionary and GAIA reference manual have changed a lot since v8p1. My colleagues hardly work for this new module.

Hope this helps,

Chi-Tuan

PS: I am not a Professor, just a Doctor.