TELEMAC-MASCARET Forum: heterogeneous friction (1/1)

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TOPIC: heterogeneous friction

heterogeneous friction 11 years 9 months ago #10530

fbatif

Hi,
I've a question about friction in telemac3d
I made a run on a "large" area with telemac2D and I would like to make a run in 3D of a small area of the 2D area.
In telemac2d I implemented an heterogeneous friction and I would like to do the same with telemac3d but it seams more difficult.
Am I wrong or there is not the possibity to read a file in 3d as in 2d with 'FICHIER DE DONNEES POUR LE FROTTEMENT'?
Thanks for your help
François

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heterogeneous friction 11 years 9 months ago #10532

jmhervouet	Hello, Telemac-2D and 3D can read the friction coefficient in the geometry file, as they read the bathymetry, so could this be a solution for you ? JMH
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heterogeneous friction 11 years 9 months ago #10534

fbatif	Indeed it can be a solution but I will have to generate a new geometry file each time i would like to change the friction right? Can you tell me what is the name of the variable to add in the geometry file for the friction, i didn't find the answer in the manuals. Thank you François
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heterogeneous friction 11 years 9 months ago #10535

jmhervouet

Hello,

The name of the variable must start with 'FROTTEMENT ' or 'BOTTOM FRICTION ' (16 characters, the 16 characters of unit are not checked). This can be seen in library BIEF, subroutine FONSTR. At this level it would be possible to give zone numbers (integers coded as reals, and recovered as integers with function NINT) instead of friction coefficients, then at the end of FONSTR you could give different values depending on the zone number.

Regards,

Jean-Michel Hervouet

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heterogeneous friction 11 years 9 months ago #10538

fbatif	Hello, Finally I just add the friction in the bathymetry. I try to add integers instead of friction and modify them after in the subroutine FONSTR but I failed... I did not understand which variable contains the friction in fonstr. It's first read in W but after the bottom level is read in W and i don't unerstand where friction is recorded... regards, François
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heterogeneous friction 11 years 9 months ago #10539

jmhervouet	Hello, The friction, whatever the formula chosen, is stored in the bief_obj structure CHESTR (so CHESTR%R to have the double precision array), W is just a work array of reals to read in the file. Regards, JMH
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heterogeneous friction 11 years 9 months ago #10540

fbatif	once again i forgot %R... Thanks a lot
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heterogeneous friction 10 years 2 weeks ago #17470

smk.svks OFFLINE Senior Boarder Posts: 93 Thank you received: 1	Hi, I used heterogeneous bottom friction values,using the "BOTTOM FRICTION" in my geometry file and used it for 2D simulation. When I use the same geometry file for 3D simulation, I am not able to see the "bottom friction" in the 3D results file !!! What is the reason ? Should I use any keyword !!!!
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heterogeneous friction 10 years 2 weeks ago #17475

jmhervouet	Hello, Just add W in the list of VARIABLES FOR 2D GRAPHIC PRINTOUTS, but it will be in the 2D results file. Regards, JMH
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