open TELEMAC-MASCARET The mathematically superior suite of solvers

Hi,

I am studying the sediment flow into the Loire river in Orléans (France) and there are several small dams/walls in the area.

When the simulation runs, these dams are quickly washed after several iterations.

I would like to know how to define a non erodible zone aroud these dams to be sure that it whill conserve it's shape during the entire simulation.

Can we do that into Matisse, into a "cas" or a "cas_sisyphe" file, into Blue Kenue, with the same technique as the one used for the variable Strikler coefficient for the dams (what are the FRENCH keywords), or something else?

Thanks a lot.

Hi
In Sisyphe, the bottom was define by 2 values called ZF and ZS. One is for the bottom level and the second one for the Hard bottom level (Non erodible bed).
By default, Sisyphe consider 100m for the layer of erodible material.
I'm not sure if it's possible to use a similar technique as the friction coefficient to define this parameter, but I'm sure it's possible to do this by a modification of noerod.f subroutine (in which the default value of ZS is done.
In this subroutine, you could locally set the two values at the same level (the bottom level) to avoid local erosion.

Last advise, have a look into the manual to see the different options that exist for the treatment of non erodible bed

Regards

Hello,

The "noerod" subroutine call for "OV" in which the treatment of the non-erodible is done.
Where this latter is located ?
Indeed I can't find it in the sisyphe source file.

Many thanks in advance.

Alexis

Hi
OV is in bief directory
This is not the treatment of non erodible area but just a subroutine which makes operations on vectors
In the begining ofthe call, you ahve the asked operation.
For the non-erodible area, by defaul you should have something like ZR=ZF-100 which is done by an operation like X=Y+C with X=ZR, Y=ZF and C=-100)

Regards

Ok, but which subroutine account for the "choix" of the treatment of non-erodible rigid beds then.
I would like to have a look at the equations.

Thank you for directing me.

Regards.

Alexis

Hello,

From version 6.0 on, there is no choice for the treatment of rigid beds. The Exner equation is solved by numerical schemes that ensure positivity of the sediment thickness. This means that the non erodible bed will naturally never be eroded, without specific treatment as was done before. The new algorithms behind this will be presented in the IARH congress in Brisbane next week, they are also used for ensuring positive water depths on tidal flats.

With best regards,

Jean-Michel Hervouet

Jean-Michel,

Will a report related to this schemes be available on the net then?

With best regards too,

Alexis

Hello,

Yes, it is in the release notes of version 6.0, I'll send it immediately to the webmaster so that it appears in the download section.

With best regards,

Jean-Michel Hervouet